From 319438e2f206036ee0cddf401dd50f3b2a3ae117 Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Fri, 16 Dec 2016 02:29:56 +0100
Subject: swscale: save ebx register when it is not available

Configure checks if the ebx register can be used for asm and it has to
be saved if and only if this is not the case.
Without this the build fails when configuring with --toolchain=hardened
--disable-pic on i386 using gcc 4.8:
error: PIC register clobbered by '%ebx' in 'asm'

In that case gcc 4.8 reserves the ebx register for the GOT needed for
PIE, so it can't be used in asm directly.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
---
 libswscale/x86/hscale_fast_bilinear_simd.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

(limited to 'libswscale')

diff --git a/libswscale/x86/hscale_fast_bilinear_simd.c b/libswscale/x86/hscale_fast_bilinear_simd.c
index 2cba5f0a1c..60a2cbfc50 100644
--- a/libswscale/x86/hscale_fast_bilinear_simd.c
+++ b/libswscale/x86/hscale_fast_bilinear_simd.c
@@ -199,7 +199,7 @@ void ff_hyscale_fast_mmxext(SwsContext *c, int16_t *dst,
 #if ARCH_X86_64
     uint64_t retsave;
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
     uint64_t ebxsave;
 #endif
 #endif
@@ -209,7 +209,7 @@ void ff_hyscale_fast_mmxext(SwsContext *c, int16_t *dst,
         "mov               -8(%%rsp), %%"FF_REG_a"    \n\t"
         "mov            %%"FF_REG_a", %5              \n\t"  // retsave
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
         "mov            %%"FF_REG_b", %5              \n\t"  // ebxsave
 #endif
 #endif
@@ -255,7 +255,7 @@ void ff_hyscale_fast_mmxext(SwsContext *c, int16_t *dst,
         "mov                      %5, %%"FF_REG_a" \n\t"
         "mov            %%"FF_REG_a", -8(%%rsp)    \n\t"
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
         "mov                      %5, %%"FF_REG_b" \n\t"
 #endif
 #endif
@@ -264,12 +264,12 @@ void ff_hyscale_fast_mmxext(SwsContext *c, int16_t *dst,
 #if ARCH_X86_64
           ,"m"(retsave)
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
           ,"m" (ebxsave)
 #endif
 #endif
         : "%"FF_REG_a, "%"FF_REG_c, "%"FF_REG_d, "%"FF_REG_S, "%"FF_REG_D
-#if ARCH_X86_64 || !defined(PIC)
+#if ARCH_X86_64 || HAVE_EBX_AVAILABLE
          ,"%"FF_REG_b
 #endif
     );
@@ -289,7 +289,7 @@ void ff_hcscale_fast_mmxext(SwsContext *c, int16_t *dst1, int16_t *dst2,
 #if ARCH_X86_64
     DECLARE_ALIGNED(8, uint64_t, retsave);
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
     DECLARE_ALIGNED(8, uint64_t, ebxsave);
 #endif
 #endif
@@ -298,7 +298,7 @@ void ff_hcscale_fast_mmxext(SwsContext *c, int16_t *dst1, int16_t *dst2,
         "mov          -8(%%rsp), %%"FF_REG_a"    \n\t"
         "mov       %%"FF_REG_a", %7              \n\t"  // retsave
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
         "mov       %%"FF_REG_b", %7              \n\t"  // ebxsave
 #endif
 #endif
@@ -332,7 +332,7 @@ void ff_hcscale_fast_mmxext(SwsContext *c, int16_t *dst1, int16_t *dst2,
         "mov                    %7, %%"FF_REG_a" \n\t"
         "mov          %%"FF_REG_a", -8(%%rsp)    \n\t"
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
         "mov %7, %%"FF_REG_b"    \n\t"
 #endif
 #endif
@@ -341,12 +341,12 @@ void ff_hcscale_fast_mmxext(SwsContext *c, int16_t *dst1, int16_t *dst2,
 #if ARCH_X86_64
           ,"m"(retsave)
 #else
-#if defined(PIC)
+#if !HAVE_EBX_AVAILABLE
           ,"m" (ebxsave)
 #endif
 #endif
         : "%"FF_REG_a, "%"FF_REG_c, "%"FF_REG_d, "%"FF_REG_S, "%"FF_REG_D
-#if ARCH_X86_64 || !defined(PIC)
+#if ARCH_X86_64 || HAVE_EBX_AVAILABLE
          ,"%"FF_REG_b
 #endif
     );
-- 
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