tcg: Introduce negsetcond opcodes

Introduce a new opcode for negative setcond.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 40 insertions, 1 deletions

diff --git a/tcg/optimize.c b/tcg/optimize.c
index bbd9bb64c6..3013eb04e6 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1567,14 +1567,22 @@ static bool fold_movcond(OptContext *ctx, TCGOp *op)
     if (arg_is_const(op->args[3]) && arg_is_const(op->args[4])) {
         uint64_t tv = arg_info(op->args[3])->val;
         uint64_t fv = arg_info(op->args[4])->val;
-        TCGOpcode opc;
+        TCGOpcode opc, negopc = 0;
 
         switch (ctx->type) {
         case TCG_TYPE_I32:
             opc = INDEX_op_setcond_i32;
+            if (TCG_TARGET_HAS_negsetcond_i32) {
+                negopc = INDEX_op_negsetcond_i32;
+            }
+            tv = (int32_t)tv;
+            fv = (int32_t)fv;
             break;
         case TCG_TYPE_I64:
             opc = INDEX_op_setcond_i64;
+            if (TCG_TARGET_HAS_negsetcond_i64) {
+                negopc = INDEX_op_negsetcond_i64;
+            }
             break;
         default:
             g_assert_not_reached();
@@ -1586,6 +1594,14 @@ static bool fold_movcond(OptContext *ctx, TCGOp *op)
         } else if (fv == 1 && tv == 0) {
             op->opc = opc;
             op->args[3] = tcg_invert_cond(cond);
+        } else if (negopc) {
+            if (tv == -1 && fv == 0) {
+                op->opc = negopc;
+                op->args[3] = cond;
+            } else if (fv == -1 && tv == 0) {
+                op->opc = negopc;
+                op->args[3] = tcg_invert_cond(cond);
+            }
         }
     }
     return false;
@@ -1796,6 +1812,26 @@ static bool fold_setcond(OptContext *ctx, TCGOp *op)
     return false;
 }
 
+static bool fold_negsetcond(OptContext *ctx, TCGOp *op)
+{
+    TCGCond cond = op->args[3];
+    int i;
+
+    if (swap_commutative(op->args[0], &op->args[1], &op->args[2])) {
+        op->args[3] = cond = tcg_swap_cond(cond);
+    }
+
+    i = do_constant_folding_cond(ctx->type, op->args[1], op->args[2], cond);
+    if (i >= 0) {
+        return tcg_opt_gen_movi(ctx, op, op->args[0], -i);
+    }
+
+    /* Value is {0,-1} so all bits are repetitions of the sign. */
+    ctx->s_mask = -1;
+    return false;
+}
+
+
 static bool fold_setcond2(OptContext *ctx, TCGOp *op)
 {
     TCGCond cond = op->args[5];
@@ -2253,6 +2289,9 @@ void tcg_optimize(TCGContext *s)
         CASE_OP_32_64(setcond):
             done = fold_setcond(&ctx, op);
             break;
+        CASE_OP_32_64(negsetcond):
+            done = fold_negsetcond(&ctx, op);
+            break;
         case INDEX_op_setcond2_i32:
             done = fold_setcond2(&ctx, op);
             break;