44 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			44 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|   | // Copyright 2018 The Go Authors. All rights reserved.
 | ||
|  | // Use of this source code is governed by a BSD-style
 | ||
|  | // license that can be found in the LICENSE file.
 | ||
|  | 
 | ||
|  | // +build 386 amd64 amd64p32
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|  | // +build gccgo
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|  | 
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|  | #include <cpuid.h>
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|  | #include <stdint.h>
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|  | 
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|  | // Need to wrap __get_cpuid_count because it's declared as static.
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|  | int | ||
|  | gccgoGetCpuidCount(uint32_t leaf, uint32_t subleaf, | ||
|  |                    uint32_t *eax, uint32_t *ebx, | ||
|  |                    uint32_t *ecx, uint32_t *edx) | ||
|  | { | ||
|  | 	return __get_cpuid_count(leaf, subleaf, eax, ebx, ecx, edx); | ||
|  | } | ||
|  | 
 | ||
|  | // xgetbv reads the contents of an XCR (Extended Control Register)
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|  | // specified in the ECX register into registers EDX:EAX.
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|  | // Currently, the only supported value for XCR is 0.
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|  | //
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|  | // TODO: Replace with a better alternative:
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|  | //
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|  | //     #include <xsaveintrin.h>
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|  | //
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|  | //     #pragma GCC target("xsave")
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|  | //
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|  | //     void gccgoXgetbv(uint32_t *eax, uint32_t *edx) {
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|  | //       unsigned long long x = _xgetbv(0);
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|  | //       *eax = x & 0xffffffff;
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|  | //       *edx = (x >> 32) & 0xffffffff;
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|  | //     }
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|  | //
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|  | // Note that _xgetbv is defined starting with GCC 8.
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|  | void | ||
|  | gccgoXgetbv(uint32_t *eax, uint32_t *edx) | ||
|  | { | ||
|  | 	__asm("  xorl %%ecx, %%ecx\n" | ||
|  | 	      "  xgetbv" | ||
|  | 	    : "=a"(*eax), "=d"(*edx)); | ||
|  | } |