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Jit_Integer: rlwinmx: Generalize byte/word extract plus shift case

This commit is contained in:
MerryMage 2020-12-27 14:36:23 +00:00
parent 263784639b
commit 11643ee2f0
1 changed files with 8 additions and 6 deletions
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14
Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
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@ -1535,7 +1535,9 @@ void Jit64::rlwinmx(UGeckoInstruction inst)
const bool left_shift = inst.SH && inst.MB == 0 && inst.ME == 31 - inst.SH;
const bool right_shift = inst.SH && inst.ME == 31 && inst.MB == 32 - inst.SH;
const u32 mask = MakeRotationMask(inst.MB, inst.ME);
const u32 prerotate_mask = Common::RotateRight(mask, inst.SH);
const bool simple_mask = mask == 0xff || mask == 0xffff;
const bool simple_prerotate_mask = prerotate_mask == 0xff || prerotate_mask == 0xffff;
// In case of a merged branch, track whether or not we've set flags.
// If not, we need to do a test later to get them.
bool needs_test = true;
@ -1557,13 +1559,13 @@ void Jit64::rlwinmx(UGeckoInstruction inst)
MOVZX(32, mask_size, Ra, Rs.ExtractWithByteOffset(inst.SH ? (32 - inst.SH) >> 3 : 0));
needs_sext = false;
}
// another optimized special case: byte/word extract plus shift
else if (((mask >> inst.SH) << inst.SH) == mask && !left_shift &&
((mask >> inst.SH) == 0xff || (mask >> inst.SH) == 0xffff))
// another optimized special case: byte/word extract plus rotate
else if (simple_prerotate_mask && !left_shift)
{
MOVZX(32, mask_size, Ra, Rs);
SHL(32, Ra, Imm8(inst.SH));
needs_sext = inst.SH + mask_size >= 32;
MOVZX(32, prerotate_mask == 0xff ? 8 : 16, Ra, Rs);
if (inst.SH)
ROL(32, Ra, Imm8(inst.SH));
needs_sext = (mask & 0x80000000) != 0;
}
else
{