kc3-lang/libjpeg-turbo/simd/i386/jsimdcpu.asm

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• Hash : eb753630
  Author :
  Date : 2024-08-31T16:50:08
  

  Update URLs
  
  - Eliminate unnecessary "www."
  - Use HTTPS.
  - Update Java, MSYS, tdm-gcc, and NSIS URLs.
  - Update URL and title of Agner Fog's assembly language optimization
    manual.
  - Remove extraneous information about MASM and Borland Turbo Assembler
    and outdated NASM URLs from the x86 assembly headers, and mention
    Yasm.
  

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• simd/i386/jsimdcpu.asm

• ;
  ; jsimdcpu.asm - SIMD instruction support check
  ;
  ; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
  ; Copyright (C) 2016, D. R. Commander.
  ;
  ; Based on the x86 SIMD extension for IJG JPEG library
  ; Copyright (C) 1999-2006, MIYASAKA Masaru.
  ; For conditions of distribution and use, see copyright notice in jsimdext.inc
  ;
  ; This file should be assembled with NASM (Netwide Assembler) or Yasm.
  
  %include "jsimdext.inc"
  
  ; --------------------------------------------------------------------------
      SECTION     SEG_TEXT
      BITS        32
  ;
  ; Check if the CPU supports SIMD instructions
  ;
  ; GLOBAL(unsigned int)
  ; jpeg_simd_cpu_support(void)
  ;
  
      align       32
      GLOBAL_FUNCTION(jpeg_simd_cpu_support)
  
  EXTN(jpeg_simd_cpu_support):
      push        ebx
  ;   push        ecx                     ; need not be preserved
  ;   push        edx                     ; need not be preserved
  ;   push        esi                     ; unused
      push        edi
  
      xor         edi, edi                ; simd support flag
  
      pushfd
      pop         eax
      mov         edx, eax
      xor         eax, 1<<21              ; flip ID bit in EFLAGS
      push        eax
      popfd
      pushfd
      pop         eax
      xor         eax, edx
      jz          near .return            ; CPUID is not supported
  
      ; Check whether CPUID leaf 07H is supported
      ; (leaf 07H is used to check for AVX2 instruction support)
      xor         eax, eax
      cpuid
      test        eax, eax
      jz          near .return
      cmp         eax, 7
      jl          short .no_avx2          ; Maximum leaf < 07H
  
      ; Check for AVX2 instruction support
      mov         eax, 7
      xor         ecx, ecx
      cpuid
      mov         eax, ebx
      test        eax, 1<<5               ; bit5:AVX2
      jz          short .no_avx2
  
      ; Check for AVX2 O/S support
      mov         eax, 1
      xor         ecx, ecx
      cpuid
      test        ecx, 1<<27
      jz          short .no_avx2          ; O/S does not support XSAVE
      test        ecx, 1<<28
      jz          short .no_avx2          ; CPU does not support AVX2
  
      xor         ecx, ecx
      xgetbv
      and         eax, 6
      cmp         eax, 6                  ; O/S does not manage XMM/YMM state
                                          ; using XSAVE
      jnz         short .no_avx2
  
      or          edi, JSIMD_AVX2
  .no_avx2:
  
      ; Check CPUID leaf 01H for MMX, SSE, and SSE2 support
      xor         eax, eax
      inc         eax
      cpuid
      mov         eax, edx                ; eax = Standard feature flags
  
      ; Check for MMX instruction support
      test        eax, 1<<23              ; bit23:MMX
      jz          short .no_mmx
      or          edi, byte JSIMD_MMX
  .no_mmx:
      test        eax, 1<<25              ; bit25:SSE
      jz          short .no_sse
      or          edi, byte JSIMD_SSE
  .no_sse:
      test        eax, 1<<26              ; bit26:SSE2
      jz          short .no_sse2
      or          edi, byte JSIMD_SSE2
  .no_sse2:
  
      ; Check for 3DNow! instruction support
      mov         eax, 0x80000000
      cpuid
      cmp         eax, 0x80000000
      jbe         short .return
  
      mov         eax, 0x80000001
      cpuid
      mov         eax, edx                ; eax = Extended feature flags
  
      test        eax, 1<<31              ; bit31:3DNow!(vendor independent)
      jz          short .no_3dnow
      or          edi, byte JSIMD_3DNOW
  .no_3dnow:
  
  .return:
      mov         eax, edi
  
      pop         edi
  ;   pop         esi                     ; unused
  ;   pop         edx                     ; need not be preserved
  ;   pop         ecx                     ; need not be preserved
      pop         ebx
      ret
  
  ; For some reason, the OS X linker does not honor the request to align the
  ; segment unless we do this.
      align       32
  

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