[Qemu-devel] [PATCH v3 16/29] tcg-aarch64: Support add2, sub2

[Richard Henderson <rth@twiddle.net>]

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/aarch64/tcg-target.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++
 tcg/aarch64/tcg-target.h |  8 ++---
 2 files changed, 82 insertions(+), 4 deletions(-)

diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c
index 0dc3fee..0587765 100644
--- a/tcg/aarch64/tcg-target.c
+++ b/tcg/aarch64/tcg-target.c
@@ -110,6 +110,7 @@ static inline void patch_reloc(uint8_t *code_ptr, int type,
 #define TCG_CT_CONST_AIMM 0x200
 #define TCG_CT_CONST_LIMM 0x400
 #define TCG_CT_CONST_ZERO 0x800
+#define TCG_CT_CONST_MONE 0x1000
 
 /* parse target specific constraints */
 static int target_parse_constraint(TCGArgConstraint *ct,
@@ -143,6 +144,9 @@ static int target_parse_constraint(TCGArgConstraint *ct,
     case 'L': /* Valid for logical immediate.  */
         ct->ct |= TCG_CT_CONST_LIMM;
         break;
+    case 'M': /* minus one */
+        ct->ct |= TCG_CT_CONST_MONE;
+        break;
     case 'Z': /* zero */
         ct->ct |= TCG_CT_CONST_ZERO;
         break;
@@ -200,6 +204,9 @@ static int tcg_target_const_match(tcg_target_long val,
     if ((ct & TCG_CT_CONST_ZERO) && val == 0) {
         return 1;
     }
+    if ((ct & TCG_CT_CONST_MONE) && val == -1) {
+        return 1;
+    }
 
     return 0;
 }
@@ -279,6 +286,10 @@ typedef enum {
     INSN_SUB   = 0x4b000000,
     INSN_SUBS  = 0x6b000000,
 
+    /* Add/subtract with carry instructions */
+    INSN_ADC   = 0x1a000000,
+    INSN_SBC   = 0x5a000000,
+
     /* Data-processing (2 source) instructions */
     INSN_LSLV  = 0x1ac02000,
     INSN_LSRV  = 0x1ac02400,
@@ -848,6 +859,47 @@ static void tcg_out_addsubi(TCGContext *s, int ext, TCGReg rd,
     tcg_fmt_Rdn_aimm(s, insn, ext, rd, rn, aimm);
 }
 
+static inline void tcg_out_addsub2(TCGContext *s, int ext, TCGReg rl,
+                                   TCGReg rh, TCGReg al, TCGReg ah,
+                                   tcg_target_long bl, tcg_target_long bh,
+                                   bool const_bl, bool const_bh, bool sub)
+{
+    TCGReg orig_rl = rl;
+    AArch64Insn insn;
+
+    if (rl == ah || (!const_bh && rl == bh)) {
+        rl = TCG_REG_TMP;
+    }
+
+    if (const_bl) {
+        insn = INSN_ADDSI;
+        if ((bl < 0) ^ sub) {
+            insn = INSN_SUBSI;
+            bl = -bl;
+        }
+        tcg_fmt_Rdn_aimm(s, insn, ext, rl, al, bl);
+    } else {
+        tcg_fmt_Rdnm(s, sub ? INSN_SUBS : INSN_ADDS, ext, rl, al, bl);
+    }
+
+    insn = INSN_ADC;
+    if (const_bh) {
+        /* Note that the only two constants we support are 0 and -1, and
+           that SBC = rn + ~rm + c, so adc -1 is sbc 0, and vice-versa.  */
+        if ((bh != 0) ^ sub) {
+            insn = INSN_SBC;
+        }
+        bh = TCG_REG_XZR;
+    } else if (sub) {
+        insn = INSN_SBC;
+    }
+    tcg_fmt_Rdnm(s, insn, ext, rh, ah, bh);
+
+    if (rl != orig_rl) {
+        tcg_out_movr(s, ext, orig_rl, rl);
+    }
+}
+
 static inline void tcg_out_nop(TCGContext *s)
 {
     tcg_out32(s, 0xd503201f);
@@ -1503,6 +1555,27 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_dep(s, ext, a0, REG0(2), args[3], args[4]);
         break;
 
+    case INDEX_op_add2_i32:
+        a2 = (int32_t)args[4];
+        c2 = false;
+        goto do_addsub2;
+    case INDEX_op_add2_i64:
+        a2 = args[4];
+        c2 = false;
+        goto do_addsub2;
+    case INDEX_op_sub2_i32:
+        a2 = (int32_t)args[4];
+        c2 = true;
+        goto do_addsub2;
+    case INDEX_op_sub2_i64:
+        a2 = args[4];
+        c2 = true;
+        goto do_addsub2;
+    do_addsub2:
+        tcg_out_addsub2(s, ext, a0, a1, REG0(2), REG0(3), a2,
+                        args[5], const_args[4], const_args[5], c2);
+        break;
+
     case INDEX_op_mov_i64:
     case INDEX_op_mov_i32:
     case INDEX_op_movi_i64:
@@ -1625,6 +1698,11 @@ static const TCGTargetOpDef aarch64_op_defs[] = {
     { INDEX_op_deposit_i32, { "r", "0", "rZ" } },
     { INDEX_op_deposit_i64, { "r", "0", "rZ" } },
 
+    { INDEX_op_add2_i32, { "r", "r", "rZ", "rZ", "rwA", "rwMZ" } },
+    { INDEX_op_add2_i64, { "r", "r", "rZ", "rZ", "rA", "rMZ" } },
+    { INDEX_op_sub2_i32, { "r", "r", "rZ", "rZ", "rwA", "rwMZ" } },
+    { INDEX_op_sub2_i64, { "r", "r", "rZ", "rZ", "rA", "rMZ" } },
+
     { -1 },
 };
 
diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
index 712e4e7..05e43e4 100644
--- a/tcg/aarch64/tcg-target.h
+++ b/tcg/aarch64/tcg-target.h
@@ -57,8 +57,8 @@ typedef enum {
 #define TCG_TARGET_HAS_nor_i32          0
 #define TCG_TARGET_HAS_deposit_i32      1
 #define TCG_TARGET_HAS_movcond_i32      1
-#define TCG_TARGET_HAS_add2_i32         0
-#define TCG_TARGET_HAS_sub2_i32         0
+#define TCG_TARGET_HAS_add2_i32         1
+#define TCG_TARGET_HAS_sub2_i32         1
 #define TCG_TARGET_HAS_mulu2_i32        0
 #define TCG_TARGET_HAS_muls2_i32        0
 #define TCG_TARGET_HAS_muluh_i32        0
@@ -85,8 +85,8 @@ typedef enum {
 #define TCG_TARGET_HAS_nor_i64          0
 #define TCG_TARGET_HAS_deposit_i64      1
 #define TCG_TARGET_HAS_movcond_i64      1
-#define TCG_TARGET_HAS_add2_i64         0
-#define TCG_TARGET_HAS_sub2_i64         0
+#define TCG_TARGET_HAS_add2_i64         1
+#define TCG_TARGET_HAS_sub2_i64         1
 #define TCG_TARGET_HAS_mulu2_i64        0
 #define TCG_TARGET_HAS_muls2_i64        0
 #define TCG_TARGET_HAS_muluh_i64        0
-- 
1.8.3.1