[Qemu-devel] [PATCH 1/6] target-ppc: Special Case of rlwimi Should Use Deposit

[Tom Musta <tommusta@gmail.com>]

The special case of rlwimi where MB <= ME and SH = 31-ME can be implemented
with a single TCG deposit operation.  This replaces the less general case
of SH = MB = 0 and ME = 31.

Signed-off-by: Tom Musta <tommusta@gmail.com>
Suggested-by: Richard Henderson <rth@twiddle.net>
---
 target-ppc/translate.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 47dc903..095b83c 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -1636,12 +1636,9 @@ static void gen_rlwimi(DisasContext *ctx)
     mb = MB(ctx->opcode);
     me = ME(ctx->opcode);
     sh = SH(ctx->opcode);
-    if (likely(sh == 0 && mb == 0 && me == 31)) {
-#if defined(TARGET_PPC64)
-        tcg_gen_mov_i64(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
-#else
-        tcg_gen_ext32u_tl(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
-#endif
+    if (likely(sh == (31-me) && mb <= me)) {
+        tcg_gen_deposit_tl(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rA(ctx->opcode)],
+                           cpu_gpr[rS(ctx->opcode)], sh, me - mb + 1);
     } else {
         target_ulong mask;
         TCGv t1;
-- 
1.7.1