[PATCH 04/12] tcg/i386: Do not expand cmp_vec early

[Richard Henderson <richard.henderson@linaro.org>]

Move most of expansion to opcode generation, leaving the
conversion of unsigned to signed to be done in the early phase.
Small inefficiencies, but not incorrect results, are introduced
until cmpsel_vec is converted in the next patch.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/i386/tcg-target.c.inc | 223 +++++++++++++++++---------------------
 1 file changed, 100 insertions(+), 123 deletions(-)

diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
index af71a397b1..278e567b56 100644
--- a/tcg/i386/tcg-target.c.inc
+++ b/tcg/i386/tcg-target.c.inc
@@ -3029,6 +3029,92 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
 #undef OP_32_64
 }
 
+static int const umin_insn[4] = {
+    OPC_PMINUB, OPC_PMINUW, OPC_PMINUD, OPC_VPMINUQ
+};
+
+static int const umax_insn[4] = {
+    OPC_PMAXUB, OPC_PMAXUW, OPC_PMAXUD, OPC_VPMAXUQ
+};
+
+static bool tcg_out_cmp_vec_noinv(TCGContext *s, TCGType type, unsigned vece,
+                                  TCGReg v0, TCGReg v1, TCGReg v2, TCGCond cond)
+{
+    static int const cmpeq_insn[4] = {
+        OPC_PCMPEQB, OPC_PCMPEQW, OPC_PCMPEQD, OPC_PCMPEQQ
+    };
+    static int const cmpgt_insn[4] = {
+        OPC_PCMPGTB, OPC_PCMPGTW, OPC_PCMPGTD, OPC_PCMPGTQ
+    };
+
+    enum {
+        NEED_INV  = 1,
+        NEED_SWAP = 2,
+        NEED_UMIN = 4,
+        NEED_UMAX = 8,
+        INVALID   = 16,
+    };
+    static const uint8_t cond_fixup[16] = {
+        [0 ... 15] = INVALID,
+        [TCG_COND_EQ] = 0,
+        [TCG_COND_GT] = 0,
+        [TCG_COND_NE] = NEED_INV,
+        [TCG_COND_LE] = NEED_INV,
+        [TCG_COND_LT] = NEED_SWAP,
+        [TCG_COND_GE] = NEED_SWAP | NEED_INV,
+        [TCG_COND_LEU] = NEED_UMIN,
+        [TCG_COND_GTU] = NEED_UMIN | NEED_INV,
+        [TCG_COND_GEU] = NEED_UMAX,
+        [TCG_COND_LTU] = NEED_UMAX | NEED_INV,
+    };
+    int fixup = cond_fixup[cond];
+
+    assert(!(fixup & INVALID));
+
+    if (fixup & NEED_INV) {
+        cond = tcg_invert_cond(cond);
+    }
+
+    if (fixup & NEED_SWAP) {
+        TCGReg swap = v1;
+        v1 = v2;
+        v2 = swap;
+        cond = tcg_swap_cond(cond);
+    }
+
+    if (fixup & (NEED_UMIN | NEED_UMAX)) {
+        int op = (fixup & NEED_UMIN ? umin_insn[vece] : umax_insn[vece]);
+
+        /* avx2 does not have 64-bit min/max; adjusted during expand. */
+        assert(vece <= MO_32);
+
+        tcg_out_vex_modrm_type(s, op, TCG_TMP_VEC, v1, v2, type);
+        v2 = TCG_TMP_VEC;
+        cond = TCG_COND_EQ;
+    }
+
+    switch (cond) {
+    case TCG_COND_EQ:
+        tcg_out_vex_modrm_type(s, cmpeq_insn[vece], v0, v1, v2, type);
+        break;
+    case TCG_COND_GT:
+        tcg_out_vex_modrm_type(s, cmpgt_insn[vece], v0, v1, v2, type);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+    return fixup & NEED_INV;
+}
+
+static void tcg_out_cmp_vec(TCGContext *s, TCGType type, unsigned vece,
+                            TCGReg v0, TCGReg v1, TCGReg v2, TCGCond cond)
+{
+    if (tcg_out_cmp_vec_noinv(s, type, vece, v0, v1, v2, cond)) {
+        tcg_out_dupi_vec(s, type, vece, TCG_TMP_VEC, -1);
+        tcg_out_vex_modrm_type(s, OPC_PXOR, v0, v0, TCG_TMP_VEC, type);
+    }
+}
+
 static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
                            unsigned vecl, unsigned vece,
                            const TCGArg args[TCG_MAX_OP_ARGS],
@@ -3058,12 +3144,6 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
     static int const shift_imm_insn[4] = {
         OPC_UD2, OPC_PSHIFTW_Ib, OPC_PSHIFTD_Ib, OPC_PSHIFTQ_Ib
     };
-    static int const cmpeq_insn[4] = {
-        OPC_PCMPEQB, OPC_PCMPEQW, OPC_PCMPEQD, OPC_PCMPEQQ
-    };
-    static int const cmpgt_insn[4] = {
-        OPC_PCMPGTB, OPC_PCMPGTW, OPC_PCMPGTD, OPC_PCMPGTQ
-    };
     static int const punpckl_insn[4] = {
         OPC_PUNPCKLBW, OPC_PUNPCKLWD, OPC_PUNPCKLDQ, OPC_PUNPCKLQDQ
     };
@@ -3082,12 +3162,6 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
     static int const smax_insn[4] = {
         OPC_PMAXSB, OPC_PMAXSW, OPC_PMAXSD, OPC_VPMAXSQ
     };
-    static int const umin_insn[4] = {
-        OPC_PMINUB, OPC_PMINUW, OPC_PMINUD, OPC_VPMINUQ
-    };
-    static int const umax_insn[4] = {
-        OPC_PMAXUB, OPC_PMAXUW, OPC_PMAXUD, OPC_VPMAXUQ
-    };
     static int const rotlv_insn[4] = {
         OPC_UD2, OPC_UD2, OPC_VPROLVD, OPC_VPROLVQ
     };
@@ -3243,15 +3317,8 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
         break;
 
     case INDEX_op_cmp_vec:
-        sub = args[3];
-        if (sub == TCG_COND_EQ) {
-            insn = cmpeq_insn[vece];
-        } else if (sub == TCG_COND_GT) {
-            insn = cmpgt_insn[vece];
-        } else {
-            g_assert_not_reached();
-        }
-        goto gen_simd;
+        tcg_out_cmp_vec(s, type, vece, a0, a1, a2, args[3]);
+        break;
 
     case INDEX_op_andc_vec:
         insn = OPC_PANDN;
@@ -3971,88 +4038,19 @@ static void expand_vec_mul(TCGType type, unsigned vece,
     }
 }
 
-static bool expand_vec_cmp_noinv(TCGType type, unsigned vece, TCGv_vec v0,
-                                 TCGv_vec v1, TCGv_vec v2, TCGCond cond)
+static void expand_vec_cmp(TCGType type, unsigned vece, TCGv_vec v0,
+                           TCGv_vec v1, TCGv_vec v2, TCGCond cond)
 {
-    enum {
-        NEED_INV  = 1,
-        NEED_SWAP = 2,
-        NEED_BIAS = 4,
-        NEED_UMIN = 8,
-        NEED_UMAX = 16,
-    };
-    TCGv_vec t1, t2, t3;
-    uint8_t fixup;
+    /*
+     * Without AVX512, there are no 64-bit unsigned comparisons.
+     * We must bias the inputs so that they become signed.
+     * All other swapping and inversion are handled during code generation.
+     */
+    if (vece == MO_64 && is_unsigned_cond(cond)) {
+        TCGv_vec t1 = tcg_temp_new_vec(type);
+        TCGv_vec t2 = tcg_temp_new_vec(type);
+        TCGv_vec t3 = tcg_constant_vec(type, vece, 1ull << ((8 << vece) - 1));
 
-    switch (cond) {
-    case TCG_COND_EQ:
-    case TCG_COND_GT:
-        fixup = 0;
-        break;
-    case TCG_COND_NE:
-    case TCG_COND_LE:
-        fixup = NEED_INV;
-        break;
-    case TCG_COND_LT:
-        fixup = NEED_SWAP;
-        break;
-    case TCG_COND_GE:
-        fixup = NEED_SWAP | NEED_INV;
-        break;
-    case TCG_COND_LEU:
-        if (tcg_can_emit_vec_op(INDEX_op_umin_vec, type, vece)) {
-            fixup = NEED_UMIN;
-        } else {
-            fixup = NEED_BIAS | NEED_INV;
-        }
-        break;
-    case TCG_COND_GTU:
-        if (tcg_can_emit_vec_op(INDEX_op_umin_vec, type, vece)) {
-            fixup = NEED_UMIN | NEED_INV;
-        } else {
-            fixup = NEED_BIAS;
-        }
-        break;
-    case TCG_COND_GEU:
-        if (tcg_can_emit_vec_op(INDEX_op_umax_vec, type, vece)) {
-            fixup = NEED_UMAX;
-        } else {
-            fixup = NEED_BIAS | NEED_SWAP | NEED_INV;
-        }
-        break;
-    case TCG_COND_LTU:
-        if (tcg_can_emit_vec_op(INDEX_op_umax_vec, type, vece)) {
-            fixup = NEED_UMAX | NEED_INV;
-        } else {
-            fixup = NEED_BIAS | NEED_SWAP;
-        }
-        break;
-    default:
-        g_assert_not_reached();
-    }
-
-    if (fixup & NEED_INV) {
-        cond = tcg_invert_cond(cond);
-    }
-    if (fixup & NEED_SWAP) {
-        t1 = v1, v1 = v2, v2 = t1;
-        cond = tcg_swap_cond(cond);
-    }
-
-    t1 = t2 = NULL;
-    if (fixup & (NEED_UMIN | NEED_UMAX)) {
-        t1 = tcg_temp_new_vec(type);
-        if (fixup & NEED_UMIN) {
-            tcg_gen_umin_vec(vece, t1, v1, v2);
-        } else {
-            tcg_gen_umax_vec(vece, t1, v1, v2);
-        }
-        v2 = t1;
-        cond = TCG_COND_EQ;
-    } else if (fixup & NEED_BIAS) {
-        t1 = tcg_temp_new_vec(type);
-        t2 = tcg_temp_new_vec(type);
-        t3 = tcg_constant_vec(type, vece, 1ull << ((8 << vece) - 1));
         tcg_gen_sub_vec(vece, t1, v1, t3);
         tcg_gen_sub_vec(vece, t2, v2, t3);
         v1 = t1;
@@ -4060,26 +4058,9 @@ static bool expand_vec_cmp_noinv(TCGType type, unsigned vece, TCGv_vec v0,
         cond = tcg_signed_cond(cond);
     }
 
-    tcg_debug_assert(cond == TCG_COND_EQ || cond == TCG_COND_GT);
     /* Expand directly; do not recurse.  */
     vec_gen_4(INDEX_op_cmp_vec, type, vece,
               tcgv_vec_arg(v0), tcgv_vec_arg(v1), tcgv_vec_arg(v2), cond);
-
-    if (t1) {
-        tcg_temp_free_vec(t1);
-        if (t2) {
-            tcg_temp_free_vec(t2);
-        }
-    }
-    return fixup & NEED_INV;
-}
-
-static void expand_vec_cmp(TCGType type, unsigned vece, TCGv_vec v0,
-                           TCGv_vec v1, TCGv_vec v2, TCGCond cond)
-{
-    if (expand_vec_cmp_noinv(type, vece, v0, v1, v2, cond)) {
-        tcg_gen_not_vec(vece, v0, v0);
-    }
 }
 
 static void expand_vec_cmpsel(TCGType type, unsigned vece, TCGv_vec v0,
@@ -4088,11 +4069,7 @@ static void expand_vec_cmpsel(TCGType type, unsigned vece, TCGv_vec v0,
 {
     TCGv_vec t = tcg_temp_new_vec(type);
 
-    if (expand_vec_cmp_noinv(type, vece, t, c1, c2, cond)) {
-        /* Invert the sense of the compare by swapping arguments.  */
-        TCGv_vec x;
-        x = v3, v3 = v4, v4 = x;
-    }
+    expand_vec_cmp(type, vece, t, c1, c2, cond);
     vec_gen_4(INDEX_op_x86_vpblendvb_vec, type, vece,
               tcgv_vec_arg(v0), tcgv_vec_arg(v4),
               tcgv_vec_arg(v3), tcgv_vec_arg(t));
-- 
2.43.0