From c928e9172928f3cddab949b107dd53b6bf79555e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Reimar=20D=C3=B6ffinger?= Date: Sun, 28 Aug 2011 21:14:13 +0200 Subject: [PATCH] Hack around gcc 4.6 breaking asm using call. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit gcc 4.6 no longer decrements esp to account for local variables. Thus using call will end up overwriting some local variable. So add an extra one it can safely clobber. This is a huge hack because it's basically pure chance it works, no idea how this is supposed to be done. Fixes trac ticket #397. Signed-off-by: Reimar Döffinger --- libswscale/x86/swscale_template.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/libswscale/x86/swscale_template.c b/libswscale/x86/swscale_template.c index 35839bed03..6a143f7481 100644 --- a/libswscale/x86/swscale_template.c +++ b/libswscale/x86/swscale_template.c @@ -1963,6 +1963,10 @@ static void RENAME(hyscale_fast)(SwsContext *c, int16_t *dst, #if defined(PIC) DECLARE_ALIGNED(8, uint64_t, ebxsave); #endif + // HACK: gcc 4.6 no longer decrements esp, + // use this to make it reserve space for the call + // return address + void *dummy; __asm__ volatile( #if defined(PIC) @@ -2014,6 +2018,7 @@ static void RENAME(hyscale_fast)(SwsContext *c, int16_t *dst, #if defined(PIC) ,"m" (ebxsave) #endif + ,"m" (dummy) : "%"REG_a, "%"REG_c, "%"REG_d, "%"REG_S, "%"REG_D #if !defined(PIC) ,"%"REG_b @@ -2035,6 +2040,10 @@ static void RENAME(hcscale_fast)(SwsContext *c, int16_t *dst1, int16_t *dst2, #if defined(PIC) DECLARE_ALIGNED(8, uint64_t, ebxsave); #endif + // HACK: gcc 4.6 no longer decrements esp, + // use this to make it reserve space for the call + // return address + void *dummy; __asm__ volatile( #if defined(PIC) @@ -2074,6 +2083,7 @@ static void RENAME(hcscale_fast)(SwsContext *c, int16_t *dst1, int16_t *dst2, #if defined(PIC) ,"m" (ebxsave) #endif + ,"m" (dummy) : "%"REG_a, "%"REG_c, "%"REG_d, "%"REG_S, "%"REG_D #if !defined(PIC) ,"%"REG_b