From 41e4c0a9ad2b10fc14896447361225b410eb112e Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Sat, 5 Aug 2023 18:16:32 +0000
Subject: [PATCH] tcg/riscv: Implement negsetcond_*

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/riscv/tcg-target.c.inc | 45 ++++++++++++++++++++++++++++++++++++++
 tcg/riscv/tcg-target.h     |  4 ++--
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
index eeaeb6b6e3..232b616af3 100644
--- a/tcg/riscv/tcg-target.c.inc
+++ b/tcg/riscv/tcg-target.c.inc
@@ -936,6 +936,44 @@ static void tcg_out_setcond(TCGContext *s, TCGCond cond, TCGReg ret,
     }
 }
 
+static void tcg_out_negsetcond(TCGContext *s, TCGCond cond, TCGReg ret,
+                               TCGReg arg1, tcg_target_long arg2, bool c2)
+{
+    int tmpflags;
+    TCGReg tmp;
+
+    /* For LT/GE comparison against 0, replicate the sign bit. */
+    if (c2 && arg2 == 0) {
+        switch (cond) {
+        case TCG_COND_GE:
+            tcg_out_opc_imm(s, OPC_XORI, ret, arg1, -1);
+            arg1 = ret;
+            /* fall through */
+        case TCG_COND_LT:
+            tcg_out_opc_imm(s, OPC_SRAI, ret, arg1, TCG_TARGET_REG_BITS - 1);
+            return;
+        default:
+            break;
+        }
+    }
+
+    tmpflags = tcg_out_setcond_int(s, cond, ret, arg1, arg2, c2);
+    tmp = tmpflags & ~SETCOND_FLAGS;
+
+    /* If intermediate result is zero/non-zero: test != 0. */
+    if (tmpflags & SETCOND_NEZ) {
+        tcg_out_opc_reg(s, OPC_SLTU, ret, TCG_REG_ZERO, tmp);
+        tmp = ret;
+    }
+
+    /* Produce the 0/-1 result. */
+    if (tmpflags & SETCOND_INV) {
+        tcg_out_opc_imm(s, OPC_ADDI, ret, tmp, -1);
+    } else {
+        tcg_out_opc_reg(s, OPC_SUB, ret, TCG_REG_ZERO, tmp);
+    }
+}
+
 static void tcg_out_movcond_zicond(TCGContext *s, TCGReg ret, TCGReg test_ne,
                                    int val1, bool c_val1,
                                    int val2, bool c_val2)
@@ -1782,6 +1820,11 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_setcond(s, args[3], a0, a1, a2, c2);
         break;
 
+    case INDEX_op_negsetcond_i32:
+    case INDEX_op_negsetcond_i64:
+        tcg_out_negsetcond(s, args[3], a0, a1, a2, c2);
+        break;
+
     case INDEX_op_movcond_i32:
     case INDEX_op_movcond_i64:
         tcg_out_movcond(s, args[5], a0, a1, a2, c2,
@@ -1910,6 +1953,8 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
     case INDEX_op_xor_i64:
     case INDEX_op_setcond_i32:
     case INDEX_op_setcond_i64:
+    case INDEX_op_negsetcond_i32:
+    case INDEX_op_negsetcond_i64:
         return C_O1_I2(r, r, rI);
 
     case INDEX_op_andc_i32:
diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
index 0efb3fc0b8..c1132d178f 100644
--- a/tcg/riscv/tcg-target.h
+++ b/tcg/riscv/tcg-target.h
@@ -88,7 +88,7 @@ extern bool have_zbb;
 
 /* optional instructions */
 #define TCG_TARGET_HAS_movcond_i32      1
-#define TCG_TARGET_HAS_negsetcond_i32   0
+#define TCG_TARGET_HAS_negsetcond_i32   1
 #define TCG_TARGET_HAS_div_i32          1
 #define TCG_TARGET_HAS_rem_i32          1
 #define TCG_TARGET_HAS_div2_i32         0
@@ -124,7 +124,7 @@ extern bool have_zbb;
 #define TCG_TARGET_HAS_qemu_st8_i32     0
 
 #define TCG_TARGET_HAS_movcond_i64      1
-#define TCG_TARGET_HAS_negsetcond_i64   0
+#define TCG_TARGET_HAS_negsetcond_i64   1
 #define TCG_TARGET_HAS_div_i64          1
 #define TCG_TARGET_HAS_rem_i64          1
 #define TCG_TARGET_HAS_div2_i64         0