--- /dev/null
+/* pnggccrd.c was removed from libpng-1.2.20. */
+
+/* This code snippet is for use by configure's compilation test. */
+
+#if (!defined _MSC_VER) && \
+ defined(PNG_ASSEMBLER_CODE_SUPPORTED) && \
+ defined(PNG_MMX_CODE_SUPPORTED)
+
+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 result;
+#if defined(PNG_MMX_CODE_SUPPORTED) // superfluous, but what the heck
+ __asm__ __volatile__ (
+#if defined(__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
+#if defined(__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;
+}
+#endif
projects / opencv / blobdiff