From cc0ac0244189cfcda258cad996f468c48eca01ff 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 (cherry picked from commit c928e9172928f3cddab949b107dd53b6bf79555e) --- 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 87248e76fa..533a7416e5 100644 --- a/libswscale/x86/swscale_template.c +++ b/libswscale/x86/swscale_template.c @@ -2285,6 +2285,10 @@ 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) @@ -2336,6 +2340,7 @@ 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 @@ -2357,6 +2362,10 @@ 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) @@ -2396,6 +2405,7 @@ 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