[Qemu-devel] [PATCH v3 00/11] target/arm: Fixups for ARM_FEATURE_V8_FP16

[Qemu-devel] [PATCH v3 00/11] target/arm: Fixups for ARM_FEATURE_V8_FP16

[Richard Henderson]

Changes since v2:
  * Rebased vs target-arm.next.
  * Merged Peter's review.
  * Split out return fix as a separate patch.

Changes since v1:
  * Rebased vs master instead of tgt-arm-sve-9.
  * Alex did some additional digging through the ARM xhtml
    and came up with some additional missing instructions.
  * Everything cc'd to qemu-stable.


r~


Alex Bennée (4):
  target/arm: Implement FCMP for fp16
  target/arm: Implement FCSEL for fp16
  target/arm: Implement FMOV (immediate) for fp16
  target/arm: Fix sqrt_f16 exception raising

Richard Henderson (7):
  target/arm: Implement FMOV (general) for fp16
  target/arm: Early exit after unallocated_encoding in disas_fp_int_conv
  target/arm: Implement FCVT (scalar,integer) for fp16
  target/arm: Implement FCVT (scalar,fixed-point) for fp16
  target/arm: Introduce and use read_fp_hreg
  target/arm: Implement FP data-processing (2 source) for fp16
  target/arm: Implement FP data-processing (3 source) for fp16

 target/arm/helper-a64.h    |   2 +
 target/arm/helper.h        |   6 +
 target/arm/helper-a64.c    |  10 +
 target/arm/helper.c        |  38 +++-
 target/arm/translate-a64.c | 421 +++++++++++++++++++++++++++++++------
 5 files changed, 413 insertions(+), 64 deletions(-)

-- 
2.17.0

[Qemu-devel] [PATCH v3 01/11] target/arm: Implement FMOV (general) for fp16

[Richard Henderson]

Adding the fp16 moves to/from general registers.

Cc: qemu-stable@nongnu.org
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index b0471c842e..10d3856351 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5700,6 +5700,15 @@ static void handle_fmov(DisasContext *s, int rd, int rn, int type, bool itof)
             tcg_gen_st_i64(tcg_rn, cpu_env, fp_reg_hi_offset(s, rd));
             clear_vec_high(s, true, rd);
             break;
+        case 3:
+            /* 16 bit */
+            tmp = tcg_temp_new_i64();
+            tcg_gen_ext16u_i64(tmp, tcg_rn);
+            write_fp_dreg(s, rd, tmp);
+            tcg_temp_free_i64(tmp);
+            break;
+        default:
+            g_assert_not_reached();
         }
     } else {
         TCGv_i64 tcg_rd = cpu_reg(s, rd);
@@ -5717,6 +5726,12 @@ static void handle_fmov(DisasContext *s, int rd, int rn, int type, bool itof)
             /* 64 bits from top half */
             tcg_gen_ld_i64(tcg_rd, cpu_env, fp_reg_hi_offset(s, rn));
             break;
+        case 3:
+            /* 16 bit */
+            tcg_gen_ld16u_i64(tcg_rd, cpu_env, fp_reg_offset(s, rn, MO_16));
+            break;
+        default:
+            g_assert_not_reached();
         }
     }
 }
@@ -5756,6 +5771,12 @@ static void disas_fp_int_conv(DisasContext *s, uint32_t insn)
         case 0xa: /* 64 bit */
         case 0xd: /* 64 bit to top half of quad */
             break;
+        case 0x6: /* 16-bit float, 32-bit int */
+        case 0xe: /* 16-bit float, 64-bit int */
+            if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+                break;
+            }
+            /* fallthru */
         default:
             /* all other sf/type/rmode combinations are invalid */
             unallocated_encoding(s);
-- 
2.17.0

[Qemu-devel] [PATCH v3 02/11] target/arm: Early exit after unallocated_encoding in disas_fp_int_conv

[Richard Henderson]

No sense in emitting code after the exception.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 10d3856351..edb4dc243f 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5780,7 +5780,7 @@ static void disas_fp_int_conv(DisasContext *s, uint32_t insn)
         default:
             /* all other sf/type/rmode combinations are invalid */
             unallocated_encoding(s);
-            break;
+            return;
         }
 
         if (!fp_access_check(s)) {
-- 
2.17.0

[Qemu-devel] [PATCH v3 03/11] target/arm: Implement FCVT (scalar, integer) for fp16

[Richard Henderson]

Cc: qemu-stable@nongnu.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.h        |  6 +++
 target/arm/helper.c        | 38 ++++++++++++++-
 target/arm/translate-a64.c | 96 +++++++++++++++++++++++++++++++-------
 3 files changed, 122 insertions(+), 18 deletions(-)

diff --git a/target/arm/helper.h b/target/arm/helper.h
index 1969b37f2d..ce89968b2d 100644
--- a/target/arm/helper.h
+++ b/target/arm/helper.h
@@ -151,6 +151,10 @@ DEF_HELPER_3(vfp_touhd_round_to_zero, i64, f64, i32, ptr)
 DEF_HELPER_3(vfp_tould_round_to_zero, i64, f64, i32, ptr)
 DEF_HELPER_3(vfp_touhh, i32, f16, i32, ptr)
 DEF_HELPER_3(vfp_toshh, i32, f16, i32, ptr)
+DEF_HELPER_3(vfp_toulh, i32, f16, i32, ptr)
+DEF_HELPER_3(vfp_toslh, i32, f16, i32, ptr)
+DEF_HELPER_3(vfp_touqh, i64, f16, i32, ptr)
+DEF_HELPER_3(vfp_tosqh, i64, f16, i32, ptr)
 DEF_HELPER_3(vfp_toshs, i32, f32, i32, ptr)
 DEF_HELPER_3(vfp_tosls, i32, f32, i32, ptr)
 DEF_HELPER_3(vfp_tosqs, i64, f32, i32, ptr)
@@ -177,6 +181,8 @@ DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr)
 DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr)
 DEF_HELPER_3(vfp_sltoh, f16, i32, i32, ptr)
 DEF_HELPER_3(vfp_ultoh, f16, i32, i32, ptr)
+DEF_HELPER_3(vfp_sqtoh, f16, i64, i32, ptr)
+DEF_HELPER_3(vfp_uqtoh, f16, i64, i32, ptr)
 
 DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, ptr)
 DEF_HELPER_FLAGS_2(set_neon_rmode, TCG_CALL_NO_RWG, i32, i32, env)
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 817f9d81a0..c6fd7f9479 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11427,8 +11427,12 @@ VFP_CONV_FIX_A64(uq, s, 32, 64, uint64)
 #undef VFP_CONV_FIX_A64
 
 /* Conversion to/from f16 can overflow to infinity before/after scaling.
- * Therefore we convert to f64 (which does not round), scale,
- * and then convert f64 to f16 (which may round).
+ * Therefore we convert to f64, scale, and then convert f64 to f16; or
+ * vice versa for conversion to integer.
+ *
+ * For 16- and 32-bit integers, the conversion to f64 never rounds.
+ * For 64-bit integers, any integer that would cause rounding will also
+ * overflow to f16 infinity, so there is no double rounding problem.
  */
 
 static float16 do_postscale_fp16(float64 f, int shift, float_status *fpst)
@@ -11446,6 +11450,16 @@ float16 HELPER(vfp_ultoh)(uint32_t x, uint32_t shift, void *fpst)
     return do_postscale_fp16(uint32_to_float64(x, fpst), shift, fpst);
 }
 
+float16 HELPER(vfp_sqtoh)(uint64_t x, uint32_t shift, void *fpst)
+{
+    return do_postscale_fp16(int64_to_float64(x, fpst), shift, fpst);
+}
+
+float16 HELPER(vfp_uqtoh)(uint64_t x, uint32_t shift, void *fpst)
+{
+    return do_postscale_fp16(uint64_to_float64(x, fpst), shift, fpst);
+}
+
 static float64 do_prescale_fp16(float16 f, int shift, float_status *fpst)
 {
     if (unlikely(float16_is_any_nan(f))) {
@@ -11475,6 +11489,26 @@ uint32_t HELPER(vfp_touhh)(float16 x, uint32_t shift, void *fpst)
     return float64_to_uint16(do_prescale_fp16(x, shift, fpst), fpst);
 }
 
+uint32_t HELPER(vfp_toslh)(float16 x, uint32_t shift, void *fpst)
+{
+    return float64_to_int32(do_prescale_fp16(x, shift, fpst), fpst);
+}
+
+uint32_t HELPER(vfp_toulh)(float16 x, uint32_t shift, void *fpst)
+{
+    return float64_to_uint32(do_prescale_fp16(x, shift, fpst), fpst);
+}
+
+uint64_t HELPER(vfp_tosqh)(float16 x, uint32_t shift, void *fpst)
+{
+    return float64_to_int64(do_prescale_fp16(x, shift, fpst), fpst);
+}
+
+uint64_t HELPER(vfp_touqh)(float16 x, uint32_t shift, void *fpst)
+{
+    return float64_to_uint64(do_prescale_fp16(x, shift, fpst), fpst);
+}
+
 /* Set the current fp rounding mode and return the old one.
  * The argument is a softfloat float_round_ value.
  */
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index edb4dc243f..14f35e878a 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5511,11 +5511,11 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
                            bool itof, int rmode, int scale, int sf, int type)
 {
     bool is_signed = !(opcode & 1);
-    bool is_double = type;
     TCGv_ptr tcg_fpstatus;
-    TCGv_i32 tcg_shift;
+    TCGv_i32 tcg_shift, tcg_single;
+    TCGv_i64 tcg_double;
 
-    tcg_fpstatus = get_fpstatus_ptr(false);
+    tcg_fpstatus = get_fpstatus_ptr(type == 3);
 
     tcg_shift = tcg_const_i32(64 - scale);
 
@@ -5533,8 +5533,9 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
             tcg_int = tcg_extend;
         }
 
-        if (is_double) {
-            TCGv_i64 tcg_double = tcg_temp_new_i64();
+        switch (type) {
+        case 1: /* float64 */
+            tcg_double = tcg_temp_new_i64();
             if (is_signed) {
                 gen_helper_vfp_sqtod(tcg_double, tcg_int,
                                      tcg_shift, tcg_fpstatus);
@@ -5544,8 +5545,10 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
             }
             write_fp_dreg(s, rd, tcg_double);
             tcg_temp_free_i64(tcg_double);
-        } else {
-            TCGv_i32 tcg_single = tcg_temp_new_i32();
+            break;
+
+        case 0: /* float32 */
+            tcg_single = tcg_temp_new_i32();
             if (is_signed) {
                 gen_helper_vfp_sqtos(tcg_single, tcg_int,
                                      tcg_shift, tcg_fpstatus);
@@ -5555,6 +5558,23 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
             }
             write_fp_sreg(s, rd, tcg_single);
             tcg_temp_free_i32(tcg_single);
+            break;
+
+        case 3: /* float16 */
+            tcg_single = tcg_temp_new_i32();
+            if (is_signed) {
+                gen_helper_vfp_sqtoh(tcg_single, tcg_int,
+                                     tcg_shift, tcg_fpstatus);
+            } else {
+                gen_helper_vfp_uqtoh(tcg_single, tcg_int,
+                                     tcg_shift, tcg_fpstatus);
+            }
+            write_fp_sreg(s, rd, tcg_single);
+            tcg_temp_free_i32(tcg_single);
+            break;
+
+        default:
+            g_assert_not_reached();
         }
     } else {
         TCGv_i64 tcg_int = cpu_reg(s, rd);
@@ -5571,8 +5591,9 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
 
         gen_helper_set_rmode(tcg_rmode, tcg_rmode, tcg_fpstatus);
 
-        if (is_double) {
-            TCGv_i64 tcg_double = read_fp_dreg(s, rn);
+        switch (type) {
+        case 1: /* float64 */
+            tcg_double = read_fp_dreg(s, rn);
             if (is_signed) {
                 if (!sf) {
                     gen_helper_vfp_tosld(tcg_int, tcg_double,
@@ -5590,9 +5611,14 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
                                          tcg_shift, tcg_fpstatus);
                 }
             }
+            if (!sf) {
+                tcg_gen_ext32u_i64(tcg_int, tcg_int);
+            }
             tcg_temp_free_i64(tcg_double);
-        } else {
-            TCGv_i32 tcg_single = read_fp_sreg(s, rn);
+            break;
+
+        case 0: /* float32 */
+            tcg_single = read_fp_sreg(s, rn);
             if (sf) {
                 if (is_signed) {
                     gen_helper_vfp_tosqs(tcg_int, tcg_single,
@@ -5614,14 +5640,39 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
                 tcg_temp_free_i32(tcg_dest);
             }
             tcg_temp_free_i32(tcg_single);
+            break;
+
+        case 3: /* float16 */
+            tcg_single = read_fp_sreg(s, rn);
+            if (sf) {
+                if (is_signed) {
+                    gen_helper_vfp_tosqh(tcg_int, tcg_single,
+                                         tcg_shift, tcg_fpstatus);
+                } else {
+                    gen_helper_vfp_touqh(tcg_int, tcg_single,
+                                         tcg_shift, tcg_fpstatus);
+                }
+            } else {
+                TCGv_i32 tcg_dest = tcg_temp_new_i32();
+                if (is_signed) {
+                    gen_helper_vfp_toslh(tcg_dest, tcg_single,
+                                         tcg_shift, tcg_fpstatus);
+                } else {
+                    gen_helper_vfp_toulh(tcg_dest, tcg_single,
+                                         tcg_shift, tcg_fpstatus);
+                }
+                tcg_gen_extu_i32_i64(tcg_int, tcg_dest);
+                tcg_temp_free_i32(tcg_dest);
+            }
+            tcg_temp_free_i32(tcg_single);
+            break;
+
+        default:
+            g_assert_not_reached();
         }
 
         gen_helper_set_rmode(tcg_rmode, tcg_rmode, tcg_fpstatus);
         tcg_temp_free_i32(tcg_rmode);
-
-        if (!sf) {
-            tcg_gen_ext32u_i64(tcg_int, tcg_int);
-        }
     }
 
     tcg_temp_free_ptr(tcg_fpstatus);
@@ -5791,7 +5842,20 @@ static void disas_fp_int_conv(DisasContext *s, uint32_t insn)
         /* actual FP conversions */
         bool itof = extract32(opcode, 1, 1);
 
-        if (type > 1 || (rmode != 0 && opcode > 1)) {
+        if (rmode != 0 && opcode > 1) {
+            unallocated_encoding(s);
+            return;
+        }
+        switch (type) {
+        case 0: /* float32 */
+        case 1: /* float64 */
+            break;
+        case 3: /* float16 */
+            if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+                break;
+            }
+            /* fallthru */
+        default:
             unallocated_encoding(s);
             return;
         }
-- 
2.17.0

[Qemu-devel] [PATCH v3 04/11] target/arm: Implement FCVT (scalar, fixed-point) for fp16

[Richard Henderson]

Cc: qemu-stable@nongnu.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 14f35e878a..eb69a548e1 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5491,6 +5491,20 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
         return;
     }
 
+    switch (type) {
+    case 0: /* float32 */
+    case 1: /* float64 */
+        break;
+    case 3: /* float16 */
+        if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            break;
+        }
+        /* fallthru */
+    default:
+        unallocated_encoding(s);
+        return;
+    }
+
     if (!fp_access_check(s)) {
         return;
     }
@@ -5697,8 +5711,7 @@ static void disas_fp_fixed_conv(DisasContext *s, uint32_t insn)
     bool sf = extract32(insn, 31, 1);
     bool itof;
 
-    if (sbit || (type > 1)
-        || (!sf && scale < 32)) {
+    if (sbit || (!sf && scale < 32)) {
         unallocated_encoding(s);
         return;
     }
-- 
2.17.0

[Qemu-devel] [PATCH v3 05/11] target/arm: Introduce and use read_fp_hreg

[Richard Henderson]

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index eb69a548e1..031213bb06 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -615,6 +615,14 @@ static TCGv_i32 read_fp_sreg(DisasContext *s, int reg)
     return v;
 }
 
+static TCGv_i32 read_fp_hreg(DisasContext *s, int reg)
+{
+    TCGv_i32 v = tcg_temp_new_i32();
+
+    tcg_gen_ld16u_i32(v, cpu_env, fp_reg_offset(s, reg, MO_16));
+    return v;
+}
+
 /* Clear the bits above an N-bit vector, for N = (is_q ? 128 : 64).
  * If SVE is not enabled, then there are only 128 bits in the vector.
  */
@@ -4881,11 +4889,9 @@ static void disas_fp_csel(DisasContext *s, uint32_t insn)
 static void handle_fp_1src_half(DisasContext *s, int opcode, int rd, int rn)
 {
     TCGv_ptr fpst = NULL;
-    TCGv_i32 tcg_op = tcg_temp_new_i32();
+    TCGv_i32 tcg_op = read_fp_hreg(s, rn);
     TCGv_i32 tcg_res = tcg_temp_new_i32();
 
-    read_vec_element_i32(s, tcg_op, rn, 0, MO_16);
-
     switch (opcode) {
     case 0x0: /* FMOV */
         tcg_gen_mov_i32(tcg_res, tcg_op);
@@ -7784,13 +7790,10 @@ static void disas_simd_scalar_three_reg_diff(DisasContext *s, uint32_t insn)
         tcg_temp_free_i64(tcg_op2);
         tcg_temp_free_i64(tcg_res);
     } else {
-        TCGv_i32 tcg_op1 = tcg_temp_new_i32();
-        TCGv_i32 tcg_op2 = tcg_temp_new_i32();
+        TCGv_i32 tcg_op1 = read_fp_hreg(s, rn);
+        TCGv_i32 tcg_op2 = read_fp_hreg(s, rm);
         TCGv_i64 tcg_res = tcg_temp_new_i64();
 
-        read_vec_element_i32(s, tcg_op1, rn, 0, MO_16);
-        read_vec_element_i32(s, tcg_op2, rm, 0, MO_16);
-
         gen_helper_neon_mull_s16(tcg_res, tcg_op1, tcg_op2);
         gen_helper_neon_addl_saturate_s32(tcg_res, cpu_env, tcg_res, tcg_res);
 
@@ -8331,13 +8334,10 @@ static void disas_simd_scalar_three_reg_same_fp16(DisasContext *s,
 
     fpst = get_fpstatus_ptr(true);
 
-    tcg_op1 = tcg_temp_new_i32();
-    tcg_op2 = tcg_temp_new_i32();
+    tcg_op1 = read_fp_hreg(s, rn);
+    tcg_op2 = read_fp_hreg(s, rm);
     tcg_res = tcg_temp_new_i32();
 
-    read_vec_element_i32(s, tcg_op1, rn, 0, MO_16);
-    read_vec_element_i32(s, tcg_op2, rm, 0, MO_16);
-
     switch (fpopcode) {
     case 0x03: /* FMULX */
         gen_helper_advsimd_mulxh(tcg_res, tcg_op1, tcg_op2, fpst);
@@ -12235,11 +12235,9 @@ static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
     }
 
     if (is_scalar) {
-        TCGv_i32 tcg_op = tcg_temp_new_i32();
+        TCGv_i32 tcg_op = read_fp_hreg(s, rn);
         TCGv_i32 tcg_res = tcg_temp_new_i32();
 
-        read_vec_element_i32(s, tcg_op, rn, 0, MO_16);
-
         switch (fpop) {
         case 0x1a: /* FCVTNS */
         case 0x1b: /* FCVTMS */
-- 
2.17.0

[Qemu-devel] [PATCH v3 06/11] target/arm: Implement FP data-processing (2 source) for fp16

[Richard Henderson]

We missed all of the scalar fp16 binary operations.

Cc: qemu-stable@nongnu.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 65 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 031213bb06..1264e798a7 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5299,6 +5299,61 @@ static void handle_fp_2src_double(DisasContext *s, int opcode,
     tcg_temp_free_i64(tcg_res);
 }
 
+/* Floating-point data-processing (2 source) - half precision */
+static void handle_fp_2src_half(DisasContext *s, int opcode,
+                                int rd, int rn, int rm)
+{
+    TCGv_i32 tcg_op1;
+    TCGv_i32 tcg_op2;
+    TCGv_i32 tcg_res;
+    TCGv_ptr fpst;
+
+    tcg_res = tcg_temp_new_i32();
+    fpst = get_fpstatus_ptr(true);
+    tcg_op1 = read_fp_hreg(s, rn);
+    tcg_op2 = read_fp_hreg(s, rm);
+
+    switch (opcode) {
+    case 0x0: /* FMUL */
+        gen_helper_advsimd_mulh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x1: /* FDIV */
+        gen_helper_advsimd_divh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x2: /* FADD */
+        gen_helper_advsimd_addh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x3: /* FSUB */
+        gen_helper_advsimd_subh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x4: /* FMAX */
+        gen_helper_advsimd_maxh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x5: /* FMIN */
+        gen_helper_advsimd_minh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x6: /* FMAXNM */
+        gen_helper_advsimd_maxnumh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x7: /* FMINNM */
+        gen_helper_advsimd_minnumh(tcg_res, tcg_op1, tcg_op2, fpst);
+        break;
+    case 0x8: /* FNMUL */
+        gen_helper_advsimd_mulh(tcg_res, tcg_op1, tcg_op2, fpst);
+        tcg_gen_xori_i32(tcg_res, tcg_res, 0x8000);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    write_fp_sreg(s, rd, tcg_res);
+
+    tcg_temp_free_ptr(fpst);
+    tcg_temp_free_i32(tcg_op1);
+    tcg_temp_free_i32(tcg_op2);
+    tcg_temp_free_i32(tcg_res);
+}
+
 /* Floating point data-processing (2 source)
  *   31  30  29 28       24 23  22  21 20  16 15    12 11 10 9    5 4    0
  * +---+---+---+-----------+------+---+------+--------+-----+------+------+
@@ -5331,6 +5386,16 @@ static void disas_fp_2src(DisasContext *s, uint32_t insn)
         }
         handle_fp_2src_double(s, opcode, rd, rn, rm);
         break;
+    case 3:
+        if (!arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            unallocated_encoding(s);
+            return;
+        }
+        if (!fp_access_check(s)) {
+            return;
+        }
+        handle_fp_2src_half(s, opcode, rd, rn, rm);
+        break;
     default:
         unallocated_encoding(s);
     }
-- 
2.17.0

[Qemu-devel] [PATCH v3 07/11] target/arm: Implement FP data-processing (3 source) for fp16

[Richard Henderson]

We missed all of the scalar fp16 fma operations.

Cc: qemu-stable@nongnu.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 48 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 1264e798a7..523fcf4801 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5477,6 +5477,44 @@ static void handle_fp_3src_double(DisasContext *s, bool o0, bool o1,
     tcg_temp_free_i64(tcg_res);
 }
 
+/* Floating-point data-processing (3 source) - half precision */
+static void handle_fp_3src_half(DisasContext *s, bool o0, bool o1,
+                                int rd, int rn, int rm, int ra)
+{
+    TCGv_i32 tcg_op1, tcg_op2, tcg_op3;
+    TCGv_i32 tcg_res = tcg_temp_new_i32();
+    TCGv_ptr fpst = get_fpstatus_ptr(true);
+
+    tcg_op1 = read_fp_hreg(s, rn);
+    tcg_op2 = read_fp_hreg(s, rm);
+    tcg_op3 = read_fp_hreg(s, ra);
+
+    /* These are fused multiply-add, and must be done as one
+     * floating point operation with no rounding between the
+     * multiplication and addition steps.
+     * NB that doing the negations here as separate steps is
+     * correct : an input NaN should come out with its sign bit
+     * flipped if it is a negated-input.
+     */
+    if (o1 == true) {
+        tcg_gen_xori_i32(tcg_op3, tcg_op3, 0x8000);
+    }
+
+    if (o0 != o1) {
+        tcg_gen_xori_i32(tcg_op1, tcg_op1, 0x8000);
+    }
+
+    gen_helper_advsimd_muladdh(tcg_res, tcg_op1, tcg_op2, tcg_op3, fpst);
+
+    write_fp_sreg(s, rd, tcg_res);
+
+    tcg_temp_free_ptr(fpst);
+    tcg_temp_free_i32(tcg_op1);
+    tcg_temp_free_i32(tcg_op2);
+    tcg_temp_free_i32(tcg_op3);
+    tcg_temp_free_i32(tcg_res);
+}
+
 /* Floating point data-processing (3 source)
  *   31  30  29 28       24 23  22  21  20  16  15  14  10 9    5 4    0
  * +---+---+---+-----------+------+----+------+----+------+------+------+
@@ -5506,6 +5544,16 @@ static void disas_fp_3src(DisasContext *s, uint32_t insn)
         }
         handle_fp_3src_double(s, o0, o1, rd, rn, rm, ra);
         break;
+    case 3:
+        if (!arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            unallocated_encoding(s);
+            return;
+        }
+        if (!fp_access_check(s)) {
+            return;
+        }
+        handle_fp_3src_half(s, o0, o1, rd, rn, rm, ra);
+        break;
     default:
         unallocated_encoding(s);
     }
-- 
2.17.0

[Qemu-devel] [PATCH v3 08/11] target/arm: Implement FCMP for fp16

[Richard Henderson]

From: Alex Bennée <alex.bennee@linaro.org>

These where missed out from the rest of the half-precision work.

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[rth: Diagnose lack of FP16 before fp_access_check]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper-a64.h    |  2 +
 target/arm/helper-a64.c    | 10 +++++
 target/arm/translate-a64.c | 88 ++++++++++++++++++++++++++++++--------
 3 files changed, 83 insertions(+), 17 deletions(-)

diff --git a/target/arm/helper-a64.h b/target/arm/helper-a64.h
index b8028ac98c..9d3a907049 100644
--- a/target/arm/helper-a64.h
+++ b/target/arm/helper-a64.h
@@ -19,6 +19,8 @@
 DEF_HELPER_FLAGS_2(udiv64, TCG_CALL_NO_RWG_SE, i64, i64, i64)
 DEF_HELPER_FLAGS_2(sdiv64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
 DEF_HELPER_FLAGS_1(rbit64, TCG_CALL_NO_RWG_SE, i64, i64)
+DEF_HELPER_3(vfp_cmph_a64, i64, f16, f16, ptr)
+DEF_HELPER_3(vfp_cmpeh_a64, i64, f16, f16, ptr)
 DEF_HELPER_3(vfp_cmps_a64, i64, f32, f32, ptr)
 DEF_HELPER_3(vfp_cmpes_a64, i64, f32, f32, ptr)
 DEF_HELPER_3(vfp_cmpd_a64, i64, f64, f64, ptr)
diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
index 549ed3513e..4f8034c513 100644
--- a/target/arm/helper-a64.c
+++ b/target/arm/helper-a64.c
@@ -85,6 +85,16 @@ static inline uint32_t float_rel_to_flags(int res)
     return flags;
 }
 
+uint64_t HELPER(vfp_cmph_a64)(float16 x, float16 y, void *fp_status)
+{
+    return float_rel_to_flags(float16_compare_quiet(x, y, fp_status));
+}
+
+uint64_t HELPER(vfp_cmpeh_a64)(float16 x, float16 y, void *fp_status)
+{
+    return float_rel_to_flags(float16_compare(x, y, fp_status));
+}
+
 uint64_t HELPER(vfp_cmps_a64)(float32 x, float32 y, void *fp_status)
 {
     return float_rel_to_flags(float32_compare_quiet(x, y, fp_status));
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 523fcf4801..0ac586345e 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -4712,14 +4712,14 @@ static void disas_data_proc_reg(DisasContext *s, uint32_t insn)
     }
 }
 
-static void handle_fp_compare(DisasContext *s, bool is_double,
+static void handle_fp_compare(DisasContext *s, int size,
                               unsigned int rn, unsigned int rm,
                               bool cmp_with_zero, bool signal_all_nans)
 {
     TCGv_i64 tcg_flags = tcg_temp_new_i64();
-    TCGv_ptr fpst = get_fpstatus_ptr(false);
+    TCGv_ptr fpst = get_fpstatus_ptr(size == MO_16);
 
-    if (is_double) {
+    if (size == MO_64) {
         TCGv_i64 tcg_vn, tcg_vm;
 
         tcg_vn = read_fp_dreg(s, rn);
@@ -4736,19 +4736,35 @@ static void handle_fp_compare(DisasContext *s, bool is_double,
         tcg_temp_free_i64(tcg_vn);
         tcg_temp_free_i64(tcg_vm);
     } else {
-        TCGv_i32 tcg_vn, tcg_vm;
+        TCGv_i32 tcg_vn = tcg_temp_new_i32();
+        TCGv_i32 tcg_vm = tcg_temp_new_i32();
 
-        tcg_vn = read_fp_sreg(s, rn);
+        read_vec_element_i32(s, tcg_vn, rn, 0, size);
         if (cmp_with_zero) {
-            tcg_vm = tcg_const_i32(0);
+            tcg_gen_movi_i32(tcg_vm, 0);
         } else {
-            tcg_vm = read_fp_sreg(s, rm);
+            read_vec_element_i32(s, tcg_vm, rm, 0, size);
         }
-        if (signal_all_nans) {
-            gen_helper_vfp_cmpes_a64(tcg_flags, tcg_vn, tcg_vm, fpst);
-        } else {
-            gen_helper_vfp_cmps_a64(tcg_flags, tcg_vn, tcg_vm, fpst);
+
+        switch (size) {
+        case MO_32:
+            if (signal_all_nans) {
+                gen_helper_vfp_cmpes_a64(tcg_flags, tcg_vn, tcg_vm, fpst);
+            } else {
+                gen_helper_vfp_cmps_a64(tcg_flags, tcg_vn, tcg_vm, fpst);
+            }
+            break;
+        case MO_16:
+            if (signal_all_nans) {
+                gen_helper_vfp_cmpeh_a64(tcg_flags, tcg_vn, tcg_vm, fpst);
+            } else {
+                gen_helper_vfp_cmph_a64(tcg_flags, tcg_vn, tcg_vm, fpst);
+            }
+            break;
+        default:
+            g_assert_not_reached();
         }
+
         tcg_temp_free_i32(tcg_vn);
         tcg_temp_free_i32(tcg_vm);
     }
@@ -4769,16 +4785,35 @@ static void handle_fp_compare(DisasContext *s, bool is_double,
 static void disas_fp_compare(DisasContext *s, uint32_t insn)
 {
     unsigned int mos, type, rm, op, rn, opc, op2r;
+    int size;
 
     mos = extract32(insn, 29, 3);
-    type = extract32(insn, 22, 2); /* 0 = single, 1 = double */
+    type = extract32(insn, 22, 2);
     rm = extract32(insn, 16, 5);
     op = extract32(insn, 14, 2);
     rn = extract32(insn, 5, 5);
     opc = extract32(insn, 3, 2);
     op2r = extract32(insn, 0, 3);
 
-    if (mos || op || op2r || type > 1) {
+    if (mos || op || op2r) {
+        unallocated_encoding(s);
+        return;
+    }
+
+    switch (type) {
+    case 0:
+        size = MO_32;
+        break;
+    case 1:
+        size = MO_64;
+        break;
+    case 3:
+        size = MO_16;
+        if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            break;
+        }
+        /* fallthru */
+    default:
         unallocated_encoding(s);
         return;
     }
@@ -4787,7 +4822,7 @@ static void disas_fp_compare(DisasContext *s, uint32_t insn)
         return;
     }
 
-    handle_fp_compare(s, type, rn, rm, opc & 1, opc & 2);
+    handle_fp_compare(s, size, rn, rm, opc & 1, opc & 2);
 }
 
 /* Floating point conditional compare
@@ -4801,16 +4836,35 @@ static void disas_fp_ccomp(DisasContext *s, uint32_t insn)
     unsigned int mos, type, rm, cond, rn, op, nzcv;
     TCGv_i64 tcg_flags;
     TCGLabel *label_continue = NULL;
+    int size;
 
     mos = extract32(insn, 29, 3);
-    type = extract32(insn, 22, 2); /* 0 = single, 1 = double */
+    type = extract32(insn, 22, 2);
     rm = extract32(insn, 16, 5);
     cond = extract32(insn, 12, 4);
     rn = extract32(insn, 5, 5);
     op = extract32(insn, 4, 1);
     nzcv = extract32(insn, 0, 4);
 
-    if (mos || type > 1) {
+    if (mos) {
+        unallocated_encoding(s);
+        return;
+    }
+
+    switch (type) {
+    case 0:
+        size = MO_32;
+        break;
+    case 1:
+        size = MO_64;
+        break;
+    case 3:
+        size = MO_16;
+        if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            break;
+        }
+        /* fallthru */
+    default:
         unallocated_encoding(s);
         return;
     }
@@ -4831,7 +4885,7 @@ static void disas_fp_ccomp(DisasContext *s, uint32_t insn)
         gen_set_label(label_match);
     }
 
-    handle_fp_compare(s, type, rn, rm, false, op);
+    handle_fp_compare(s, size, rn, rm, false, op);
 
     if (cond < 0x0e) {
         gen_set_label(label_continue);
-- 
2.17.0

[Qemu-devel] [PATCH v3 09/11] target/arm: Implement FCSEL for fp16

[Richard Henderson]

From: Alex Bennée <alex.bennee@linaro.org>

These were missed out from the rest of the half-precision work.

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[rth: Fix erroneous check vs type]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 0ac586345e..85a46f7abd 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -4903,15 +4903,34 @@ static void disas_fp_csel(DisasContext *s, uint32_t insn)
     unsigned int mos, type, rm, cond, rn, rd;
     TCGv_i64 t_true, t_false, t_zero;
     DisasCompare64 c;
+    TCGMemOp sz;
 
     mos = extract32(insn, 29, 3);
-    type = extract32(insn, 22, 2); /* 0 = single, 1 = double */
+    type = extract32(insn, 22, 2);
     rm = extract32(insn, 16, 5);
     cond = extract32(insn, 12, 4);
     rn = extract32(insn, 5, 5);
     rd = extract32(insn, 0, 5);
 
-    if (mos || type > 1) {
+    if (mos) {
+        unallocated_encoding(s);
+        return;
+    }
+
+    switch (type) {
+    case 0:
+        sz = MO_32;
+        break;
+    case 1:
+        sz = MO_64;
+        break;
+    case 3:
+        sz = MO_16;
+        if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            break;
+        }
+        /* fallthru */
+    default:
         unallocated_encoding(s);
         return;
     }
@@ -4920,11 +4939,11 @@ static void disas_fp_csel(DisasContext *s, uint32_t insn)
         return;
     }
 
-    /* Zero extend sreg inputs to 64 bits now.  */
+    /* Zero extend sreg & hreg inputs to 64 bits now.  */
     t_true = tcg_temp_new_i64();
     t_false = tcg_temp_new_i64();
-    read_vec_element(s, t_true, rn, 0, type ? MO_64 : MO_32);
-    read_vec_element(s, t_false, rm, 0, type ? MO_64 : MO_32);
+    read_vec_element(s, t_true, rn, 0, sz);
+    read_vec_element(s, t_false, rm, 0, sz);
 
     a64_test_cc(&c, cond);
     t_zero = tcg_const_i64(0);
@@ -4933,7 +4952,7 @@ static void disas_fp_csel(DisasContext *s, uint32_t insn)
     tcg_temp_free_i64(t_false);
     a64_free_cc(&c);
 
-    /* Note that sregs write back zeros to the high bits,
+    /* Note that sregs & hregs write back zeros to the high bits,
        and we've already done the zero-extension.  */
     write_fp_dreg(s, rd, t_true);
     tcg_temp_free_i64(t_true);
-- 
2.17.0

[Qemu-devel] [PATCH v3 10/11] target/arm: Implement FMOV (immediate) for fp16

[Richard Henderson]

From: Alex Bennée <alex.bennee@linaro.org>

All the hard work is already done by vfp_expand_imm, we just need to
make sure we pick up the correct size.

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[rth: Merge unallocated_encoding check with TCGMemOp conversion.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 85a46f7abd..d77eda7cbc 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -5674,11 +5674,25 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
 {
     int rd = extract32(insn, 0, 5);
     int imm8 = extract32(insn, 13, 8);
-    int is_double = extract32(insn, 22, 2);
+    int type = extract32(insn, 22, 2);
     uint64_t imm;
     TCGv_i64 tcg_res;
+    TCGMemOp sz;
 
-    if (is_double > 1) {
+    switch (type) {
+    case 0:
+        sz = MO_32;
+        break;
+    case 1:
+        sz = MO_64;
+        break;
+    case 3:
+        sz = MO_16;
+        if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+            break;
+        }
+        /* fallthru */
+    default:
         unallocated_encoding(s);
         return;
     }
@@ -5701,7 +5715,7 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
         return;
     }
 
-    imm = vfp_expand_imm(MO_32 + is_double, imm8);
+    imm = vfp_expand_imm(sz, imm8);
 
     tcg_res = tcg_const_i64(imm);
     write_fp_dreg(s, rd, tcg_res);
-- 
2.17.0

[Qemu-devel] [PATCH v3 11/11] target/arm: Fix sqrt_f16 exception raising

[Richard Henderson]

From: Alex Bennée <alex.bennee@linaro.org>

We are meant to explicitly pass fpst, not cpu_env.

Cc: qemu-stable@nongnu.org
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index d77eda7cbc..009a151379 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -4976,7 +4976,8 @@ static void handle_fp_1src_half(DisasContext *s, int opcode, int rd, int rn)
         tcg_gen_xori_i32(tcg_res, tcg_op, 0x8000);
         break;
     case 0x3: /* FSQRT */
-        gen_helper_sqrt_f16(tcg_res, tcg_op, cpu_env);
+        fpst = get_fpstatus_ptr(true);
+        gen_helper_sqrt_f16(tcg_res, tcg_op, fpst);
         break;
     case 0x8: /* FRINTN */
     case 0x9: /* FRINTP */
-- 
2.17.0