Mirrors/shadPS4
1
0
Fork 0
mirror of https://github.com/shadps4-emu/shadPS4.git synced 2025-07-12 04:35:56 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Zero top bits in INSERTQ/EXTRQ

Browse source
This commit is contained in:
offtkp 2025-07-09 12:20:57 +03:00
parent df4314f831
commit 0a11060964
1 changed files with 6 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

11
src/core/cpu_patches.cpp
View file

@ -177,8 +177,7 @@ static void GenerateEXTRQ(void* /* address */, const ZydisDecodedOperand* operan
c.mov(scratch2, mask);
c.and_(scratch1, scratch2);
// Writeback to xmm register, extrq instruction says top 64-bits are undefined so we don't
// care to preserve them
// Writeback to xmm register, extrq instruction says top 64-bits are undefined but zeroed on AMD CPUs
c.vmovq(xmm_dst, scratch1);
c.pop(scratch2);
@ -307,8 +306,8 @@ static void GenerateINSERTQ(void* /* address */, const ZydisDecodedOperand* oper
// dst |= src
c.or_(scratch2, scratch1);
// Insert scratch2 into low 64 bits of dst, upper 64 bits are unaffected
c.vpinsrq(xmm_dst, xmm_dst, scratch2, 0);
// Insert scratch2 into low 64 bits of dst, upper 64 bits are undefined but zeroed on AMD CPUs
c.vmovq(xmm_dst, scratch2);
c.pop(mask);
c.pop(scratch2);
@ -374,7 +373,7 @@ static void GenerateINSERTQ(void* /* address */, const ZydisDecodedOperand* oper
c.and_(scratch2, mask);
c.or_(scratch2, scratch1);
// Upper 64 bits are undefined in insertq
// Upper 64 bits are undefined in insertq but AMD CPUs zero them
c.vmovq(xmm_dst, scratch2);
c.pop(mask);
@ -635,6 +634,7 @@ static bool TryExecuteIllegalInstruction(void* ctx, void* code_address) {
lowQWordDst >>= index;
lowQWordDst &= mask;
memset((u8*)dst + sizeof(u64), 0, sizeof(u64));
memcpy(dst, &lowQWordDst, sizeof(lowQWordDst));
Common::IncrementRip(ctx, 4);
@ -675,6 +675,7 @@ static bool TryExecuteIllegalInstruction(void* ctx, void* code_address) {
lowQWordDst &= ~(mask << index);
lowQWordDst |= lowQWordSrc << index;
memset((u8*)dst + sizeof(u64), 0, sizeof(u64));
memcpy(dst, &lowQWordDst, sizeof(lowQWordDst));
Common::IncrementRip(ctx, 4);