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[Qemu-devel] [PATCH 5/8] tcg/optimize: simplify shift/rot r, 0, a => mov
From: |
Aurelien Jarno |
Subject: |
[Qemu-devel] [PATCH 5/8] tcg/optimize: simplify shift/rot r, 0, a => movi r, 0 cases |
Date: |
Thu, 6 Sep 2012 17:00:54 +0200 |
shift/rot r, 0, a is equivalent to movi r, 0.
Signed-off-by: Aurelien Jarno <address@hidden>
---
tcg/optimize.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index c12cb2b..1698ba3 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -322,6 +322,26 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
uint16_t *tcg_opc_ptr,
break;
}
+ /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */
+ switch (op) {
+ CASE_OP_32_64(shl):
+ CASE_OP_32_64(shr):
+ CASE_OP_32_64(sar):
+ CASE_OP_32_64(rotl):
+ CASE_OP_32_64(rotr):
+ if (temps[args[1]].state == TCG_TEMP_CONST
+ && temps[args[1]].val == 0) {
+ gen_opc_buf[op_index] = op_to_movi(op);
+ tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals);
+ args += 3;
+ gen_args += 2;
+ continue;
+ }
+ break;
+ default:
+ break;
+ }
+
/* Simplify expression for "op r, a, 0 => mov r, a" cases */
switch (op) {
CASE_OP_32_64(add):
--
1.7.10.4
- [Qemu-devel] [PATCH 0/8] Improve TCG optimizer, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 1/8] tcg: improve profiler, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 4/8] tcg/optimize: simplify and r, a, 0 cases, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 2/8] tcg/optimize: split expression simplification, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 8/8] tcg/optimize: add constant folding for brcond, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 6/8] tcg/optimize: swap brcond/setcond arguments when possible, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 7/8] tcg/optimize: add constant folding for setcond, Aurelien Jarno, 2012/09/06
- [Qemu-devel] [PATCH 5/8] tcg/optimize: simplify shift/rot r, 0, a => movi r, 0 cases,
Aurelien Jarno <=
- [Qemu-devel] [PATCH 3/8] tcg/optimize: simplify or/xor r, a, 0 cases, Aurelien Jarno, 2012/09/06
- Re: [Qemu-devel] [PATCH 0/8] Improve TCG optimizer, Richard Henderson, 2012/09/06
- Re: [Qemu-devel] [PATCH 0/8] Improve TCG optimizer, Peter Maydell, 2012/09/07