[Qemu-devel] [PATCH] target-ppc: Use movcond in isel

[Richard Henderson <rth@twiddle.net>]

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-ppc/translate.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)
---
Note that this is relative to an outstanding TCG patch set.
The full tree is at

  git://github.com/rth7680/qemu.git ppc-movcond


r~
---

diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 98165e9..278c266 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -753,27 +753,20 @@ static void gen_cmpli(DisasContext *ctx)
 /* isel (PowerPC 2.03 specification) */
 static void gen_isel(DisasContext *ctx)
 {
-    TCGLabel *l1, *l2;
     uint32_t bi = rC(ctx->opcode);
-    uint32_t mask;
-    TCGv_i32 t0;
+    uint32_t mask = 0x08 >> (bi & 0x03);
+    TCGv t0 = tcg_temp_new();
+    TCGv zr;
 
-    l1 = gen_new_label();
-    l2 = gen_new_label();
+    tcg_gen_extu_i32_tl(t0, cpu_crf[bi >> 2]);
+    tcg_gen_andi_tl(t0, t0, mask);
 
-    mask = 0x08 >> (bi & 0x03);
-    t0 = tcg_temp_new_i32();
-    tcg_gen_andi_i32(t0, cpu_crf[bi >> 2], mask);
-    tcg_gen_brcondi_i32(TCG_COND_EQ, t0, 0, l1);
-    if (rA(ctx->opcode) == 0)
-        tcg_gen_movi_tl(cpu_gpr[rD(ctx->opcode)], 0);
-    else
-        tcg_gen_mov_tl(cpu_gpr[rD(ctx->opcode)], cpu_gpr[rA(ctx->opcode)]);
-    tcg_gen_br(l2);
-    gen_set_label(l1);
-    tcg_gen_mov_tl(cpu_gpr[rD(ctx->opcode)], cpu_gpr[rB(ctx->opcode)]);
-    gen_set_label(l2);
-    tcg_temp_free_i32(t0);
+    zr = tcg_const_tl(0);
+    tcg_gen_movcond_tl(TCG_COND_NE, cpu_gpr[rD(ctx->opcode)], t0, zr,
+                       rA(ctx->opcode) ? cpu_gpr[rA(ctx->opcode)] : zr,
+                       cpu_gpr[rB(ctx->opcode)]);
+    tcg_temp_free(zr);
+    tcg_temp_free(t0);
 }
 
 /* cmpb: PowerPC 2.05 specification */
-- 
2.1.0