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[Qemu-devel] [PULL 07/15] tcg/optimize: Handle known-zeros masks for AND
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PULL 07/15] tcg/optimize: Handle known-zeros masks for ANDC |
Date: |
Mon, 17 Feb 2014 19:15:57 -0600 |
Reviewed-by: Paolo Bonzini <address@hidden>
Reviewed-by: Aurelien Jarno <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/optimize.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 1b9fea5..4bea8a5 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -727,6 +727,17 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
uint16_t *tcg_opc_ptr,
mask = temps[args[1]].mask & mask;
break;
+ CASE_OP_32_64(andc):
+ /* Known-zeros does not imply known-ones. Therefore unless
+ args[2] is constant, we can't infer anything from it. */
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ mask = ~temps[args[2]].mask;
+ goto and_const;
+ }
+ /* But we certainly know nothing outside args[1] may be set. */
+ mask = temps[args[1]].mask;
+ break;
+
case INDEX_op_sar_i32:
if (temps[args[2]].state == TCG_TEMP_CONST) {
mask = (int32_t)temps[args[1]].mask >> temps[args[2]].val;
--
1.8.5.3
- [Qemu-devel] [PULL 00/15] tcg updates, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 02/15] tcg-arm: The shift count of op_rotl_i32 is in args[2] not args[1]., Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 01/15] TCG: Fix 32-bit host allocation typo, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 03/15] tcg/optimize: fix known-zero bits for right shift ops, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 04/15] tcg/optimize: fix known-zero bits optimization, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 05/15] tcg/optimize: improve known-zero bits for 32-bit ops, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 06/15] tcg/optimize: add known-zero bits compute for load ops, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 07/15] tcg/optimize: Handle known-zeros masks for ANDC,
Richard Henderson <=
- [Qemu-devel] [PULL 08/15] tcg/optimize: Simply some logical ops to NOT, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 09/15] tcg/optimize: Optmize ANDC X, Y, Y to MOV X, 0, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 10/15] tcg/optimize: Add more identity simplifications, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 11/15] disas/i386: Disassemble ANDN/SHLX/SHRX/SHAX, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 12/15] tcg/i386: Move TCG_CT_CONST_* to tcg-target.c, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 13/15] tcg/i386: Add tcg_out_vex_modrm, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 15/15] tcg/i386: Use SHLX/SHRX/SARX instructions, Richard Henderson, 2014/02/17
- [Qemu-devel] [PULL 14/15] tcg/i386: Use ANDN instruction, Richard Henderson, 2014/02/17
- Re: [Qemu-devel] [PULL 00/15] tcg updates, Kevin Wolf, 2014/02/19