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pc64: AMD64 mandates SSE support, remove the check in fpuinit()

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This commit is contained in:
cinap_lenrek 2020-12-06 21:44:26 +01:00
parent dcdb2bfb9a
commit cd38d41356
1 changed files with 18 additions and 35 deletions
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53
sys/src/9/pc64/fpu.c
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@ -30,18 +30,6 @@ extern void _fwait(void);
extern void _ldmxcsr(u32int);
extern void _stts(void);
/*
* not used, AMD64 mandated SSE
*/
static void
fpx87save(FPsave*)
{
}
static void
fpx87restore(FPsave*)
{
}
static void
fpssesave(FPsave *s)
{
@ -261,34 +249,29 @@ mathinit(void)
void
fpuinit(void)
{
uintptr cr4;
u64int cr4;
ulong regs[4];
if((m->cpuiddx & (Sse|Fxsr)) == (Sse|Fxsr)){ /* have sse fp? */
cr4 = getcr4() | CR4Osfxsr|CR4Oxmmex;
cr4 = getcr4() | CR4Osfxsr|CR4Oxmmex;
putcr4(cr4);
fpsave = fpssesave;
fprestore = fpsserestore;
if((m->cpuidcx & (Xsave|Avx)) == (Xsave|Avx) && getconf("*noavx") == nil){
cr4 |= CR4Oxsave;
putcr4(cr4);
fpsave = fpssesave;
fprestore = fpsserestore;
m->xcr0 = 7; /* x87, sse, avx */
putxcr0(m->xcr0);
fpsave = fpxsave;
fprestore = fpxrestore;
if((m->cpuidcx & (Xsave|Avx)) == (Xsave|Avx) && getconf("*noavx") == nil){
cr4 |= CR4Oxsave;
putcr4(cr4);
m->xcr0 = 7; /* x87, sse, avx */
putxcr0(m->xcr0);
fpsave = fpxsave;
fprestore = fpxrestore;
cpuid(0xd, 1, regs);
if(regs[0] & Xsaveopt)
fpsave = fpxsaveopt;
if(regs[0] & Xsaves){
fpsave = fpxsaves;
fprestore = fpxrestores;
}
cpuid(0xd, 1, regs);
if(regs[0] & Xsaveopt)
fpsave = fpxsaveopt;
if(regs[0] & Xsaves){
fpsave = fpxsaves;
fprestore = fpxrestores;
}
} else {
fpsave = fpx87save;
fprestore = fpx87restore;
}
}