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authorGlenn Randers-Pehrson <glennrp at users.sourceforge.net>2012-03-02 14:25:11 -0600
committerGlenn Randers-Pehrson <glennrp at users.sourceforge.net>2012-03-02 14:27:25 -0600
commit30d32302d0148b05a26723ee7396348ac9e5a07a (patch)
tree487e89982ed61f0534857c5e42e788c9fd016d92 /pnggccrd.c
parentd2fe2191dbb2af8a77f31682e04c09bf4ddaa446 (diff)
downloadlibpng-30d32302d0148b05a26723ee7396348ac9e5a07a.tar.gz
[libpng12] Imported from libpng-1.2.48rc02.tarv1.2.48rc02
Diffstat (limited to 'pnggccrd.c')
-rw-r--r--pnggccrd.c97
1 files changed, 5 insertions, 92 deletions
diff --git a/pnggccrd.c b/pnggccrd.c
index 51b90d0b1..033bf8b36 100644
--- a/pnggccrd.c
+++ b/pnggccrd.c
@@ -1,6 +1,6 @@
/* pnggccrd.c
*
- * Last changed in libpng 1.2.48 [February 29, 2012]
+ * Last changed in libpng 1.2.48 [March 2, 2012]
* Copyright (c) 1998-2012 Glenn Randers-Pehrson
*
* This code is released under the libpng license.
@@ -8,7 +8,7 @@
* and license in png.h
*
* This code snippet is for use by configure's compilation test. The
- * remainder of the file was removed from libpng-1.2.20.
+ * remainder of the file was removed from libpng-1.2.20.
*/
#if (!defined _MSC_VER) && \
@@ -17,96 +17,9 @@
int PNGAPI png_dummy_mmx_support(void);
-static int _mmx_supported = 2; // 0: no MMX; 1: MMX supported; 2: not tested
-
-int PNGAPI
-png_dummy_mmx_support(void) __attribute__((noinline));
-
-int PNGAPI
-png_dummy_mmx_support(void)
+int PNGAPI png_dummy_mmx_support(void)
{
- int result;
-#ifdef PNG_MMX_CODE_SUPPORTED // superfluous, but what the heck
- __asm__ __volatile__ (
-#ifdef __x86_64__
- "pushq %%rbx \n\t" // rbx gets clobbered by CPUID instruction
- "pushq %%rcx \n\t" // so does rcx...
- "pushq %%rdx \n\t" // ...and rdx (but rcx & rdx safe on Linux)
- "pushfq \n\t" // save Eflag to stack
- "popq %%rax \n\t" // get Eflag from stack into rax
- "movq %%rax, %%rcx \n\t" // make another copy of Eflag in rcx
- "xorl $0x200000, %%eax \n\t" // toggle ID bit in Eflag (i.e., bit 21)
- "pushq %%rax \n\t" // save modified Eflag back to stack
- "popfq \n\t" // restore modified value to Eflag reg
- "pushfq \n\t" // save Eflag to stack
- "popq %%rax \n\t" // get Eflag from stack
- "pushq %%rcx \n\t" // save original Eflag to stack
- "popfq \n\t" // restore original Eflag
-#else
- "pushl %%ebx \n\t" // ebx gets clobbered by CPUID instruction
- "pushl %%ecx \n\t" // so does ecx...
- "pushl %%edx \n\t" // ...and edx (but ecx & edx safe on Linux)
- "pushfl \n\t" // save Eflag to stack
- "popl %%eax \n\t" // get Eflag from stack into eax
- "movl %%eax, %%ecx \n\t" // make another copy of Eflag in ecx
- "xorl $0x200000, %%eax \n\t" // toggle ID bit in Eflag (i.e., bit 21)
- "pushl %%eax \n\t" // save modified Eflag back to stack
- "popfl \n\t" // restore modified value to Eflag reg
- "pushfl \n\t" // save Eflag to stack
- "popl %%eax \n\t" // get Eflag from stack
- "pushl %%ecx \n\t" // save original Eflag to stack
- "popfl \n\t" // restore original Eflag
-#endif
- "xorl %%ecx, %%eax \n\t" // compare new Eflag with original Eflag
- "jz 0f \n\t" // if same, CPUID instr. is not supported
-
- "xorl %%eax, %%eax \n\t" // set eax to zero
-// ".byte 0x0f, 0xa2 \n\t" // CPUID instruction (two-byte opcode)
- "cpuid \n\t" // get the CPU identification info
- "cmpl $1, %%eax \n\t" // make sure eax return non-zero value
- "jl 0f \n\t" // if eax is zero, MMX is not supported
-
- "xorl %%eax, %%eax \n\t" // set eax to zero and...
- "incl %%eax \n\t" // ...increment eax to 1. This pair is
- // faster than the instruction "mov eax, 1"
- "cpuid \n\t" // get the CPU identification info again
- "andl $0x800000, %%edx \n\t" // mask out all bits but MMX bit (23)
- "cmpl $0, %%edx \n\t" // 0 = MMX not supported
- "jz 0f \n\t" // non-zero = yes, MMX IS supported
-
- "movl $1, %%eax \n\t" // set return value to 1
- "jmp 1f \n\t" // DONE: have MMX support
-
- "0: \n\t" // .NOT_SUPPORTED: target label for jump instructions
- "movl $0, %%eax \n\t" // set return value to 0
- "1: \n\t" // .RETURN: target label for jump instructions
-#ifdef __x86_64__
- "popq %%rdx \n\t" // restore rdx
- "popq %%rcx \n\t" // restore rcx
- "popq %%rbx \n\t" // restore rbx
-#else
- "popl %%edx \n\t" // restore edx
- "popl %%ecx \n\t" // restore ecx
- "popl %%ebx \n\t" // restore ebx
-#endif
-
-// "ret \n\t" // DONE: no MMX support
- // (fall through to standard C "ret")
-
- : "=a" (result) // output list
-
- : // any variables used on input (none)
-
- // no clobber list
-// , "%ebx", "%ecx", "%edx" // GRR: we handle these manually
-// , "memory" // if write to a variable gcc thought was in a reg
-// , "cc" // "condition codes" (flag bits)
- );
- _mmx_supported = result;
-#else
- _mmx_supported = 0;
-#endif /* PNG_MMX_CODE_SUPPORTED */
-
- return _mmx_supported;
+ /* 0: no MMX; 1: MMX supported; 2: not tested */
+ return 2;
}
#endif