[patch] Patch to fix asm (cpuid and mmx usage) for PIC compliance

openmsx-x86-pic-cpuidmmx.patch (text/plain), 2.08 KB, created by Kevin F. Quinn (RETIRED) on 2005-07-24 06:00:04 UTC

--- src/HostCPU.cc.orig	2005-07-24 13:56:56.000000000 +0200
+++ src/HostCPU.cc	2005-07-24 14:00:19.000000000 +0200
@@ -23,7 +23,7 @@
 			"pushfl;"
 			"popl	%%eax;"
 			// Save current value.
-			"movl	%%eax,%%ebx;"
+			"movl	%%eax,%%ecx;"
 			// Toggle bit 21.
 			"xorl	$0x200000, %%eax;"
 			// Load EAX into EFLAGS.
@@ -33,29 +33,33 @@
 			"pushfl;"
 			"popl	%%eax;"
 			// Did bit 21 change?
-			"xor	%%ebx, %%eax;"
+			"xor	%%ecx, %%eax;"
 			"andl	$0x200000, %%eax;"
 			: "=a" (hasCPUID) // 0
 			: // no input
-			: "ebx"
+			: "ecx" // use ecx not ebx to avoid PIC abi clobber
 			);
 		if (hasCPUID) {
 			// Which CPUID calls are supported?
 			unsigned highest;
 			asm (
+				"pushl	%%ebx;"
 				"cpuid;"
+				"popl	%%ebx;"
 				: "=a" (highest) // 0
 				: "0" (0) // 1: function
-				: "ebx", "ecx", "edx"
+				: "ecx", "edx" // ebx save/restored to avoid PIC abi clobber
 				);
 			if (highest >= 1) {
 				// Get features flags.
 				unsigned features;
 				asm (
+					"pushl	%%ebx;"
 					"cpuid;"
+					"pushl	%%ebx;"
 					: "=d" (features) // 0
 					: "a" (1) // 1: function
-					: "ebx", "ecx"
+					: "ecx" // ebx save/restored to avoid PIC abi clobber
 					);
 				PRT_DEBUG("CPU flags: " << std::hex << std::setw(8) << std::setfill('0') << std::uppercase << features);
 				mmxFlag = features & 0x800000;
--- src/video/SimpleScaler.cc.orig	2005-07-24 14:35:13.000000000 +0200
+++ src/video/SimpleScaler.cc	2005-07-24 14:43:01.000000000 +0200
@@ -684,6 +684,7 @@
 			"paddw	%%mm4, %%mm0;"
 			"paddw	%%mm5, %%mm1;"
 			
+			"movd	%%eax, %%mm6;" // save eax
 			"pextrw	$0, %%mm0, %%eax;"
 			"movw	(%2,%%eax,2), %%ax;"
 			"pinsrw	$0, %%eax, %%mm0;"
@@ -711,6 +712,7 @@
 			"pextrw	$3, %%mm1, %%eax;"
 			"movw	(%2,%%eax,2), %%ax;"
 			"pinsrw	$3, %%eax, %%mm1;"
+			"movd	%%mm6, %%eax;" // restore eax
 			
 			"movntq	%%mm0,   (%3,%%ecx,2);"
 			"movntq	%%mm1,  8(%3,%%ecx,2);"
@@ -726,7 +728,7 @@
 			, "r" (dst)   // 3
 			, "m" (mask)   // 4
 			: "mm0", "mm1", "mm2", "mm3", "mm4", "mm5", "mm7"
-			, "eax", "ecx"
+			, "ecx" // eax save/restored so available for 'r'
 		);
 		return;
 	}