From d84b2a81e0b1d5c2d01f75f1398440d21da26e29 Mon Sep 17 00:00:00 2001
From: Changpeng Fang <chfang@houghton.(none)>
Date: Tue, 1 Mar 2011 12:50:46 -0800
Subject: [PATCH] Introduce flag -mavx-m128-only to generate only 128-bit avx instructions.
* config/i386/i386.opt (mavx-m128-only): New flag.
* config/i386/i386.c (ix86_preferred_simd_mode): Prefer 128-bit mode
if the flag -mavx-m128-only is turned on.
---
gcc/config/i386/i386.c | 4 ++--
gcc/config/i386/i386.opt | 4 ++++
2 files changed, 6 insertions(+), 2 deletions(-)
@@ -34747,9 +34747,9 @@ ix86_preferred_simd_mode (enum machine_mode mode)
switch (mode)
{
case SFmode:
- return TARGET_AVX ? V8SFmode : V4SFmode;
+ return TARGET_AVX ? (flag_avx_m128_only ? V4SFmode : V8SFmode) : V4SFmode;
case DFmode:
- return TARGET_AVX ? V4DFmode : V2DFmode;
+ return TARGET_AVX ? (flag_avx_m128_only ? V2DFmode : V4DFmode) : V2DFmode;
case DImode:
return V2DImode;
case SImode:
@@ -266,6 +266,10 @@ Target RejectNegative Var(flag_dispatch_scheduler)
Do dispatch scheduling if processor is bdver1 and Haifa scheduling
is selected.
+mavx-m128-only
+Target Report Var(flag_avx_m128_only) Init(0)
+Generate only 128-bit AVX instructions.
+
;; ISA support
m32
--
1.6.3.3