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b2c4bf3ff6
regularly in "normal" code, but for things like software graphics, they
make a big difference.
For the following code:
unsigned short Trans16Bit(unsigned srcA,unsigned srcB,unsigned alpha)
{
unsigned tmpA,tmpB,mixed;
tmpA = ((srcA & 0x03E0) << 15) | (srcA & 0x7C1F);
tmpB = ((srcB & 0x03E0) << 15) | (srcB & 0x7C1F);
mixed = (tmpA * alpha) + (tmpB * (32 - alpha));
return ((mixed >> 5) & 0x7C1F) | ((mixed >> 20) & 0x03E0);
}
We now generate:
_Trans16Bit:
.LBB_Trans16Bit_0: ; entry
andi. r2, r4, 31775
rlwimi r2, r4, 15, 7, 11
subfic r4, r5, 32
mullw r2, r2, r4
andi. r4, r3, 31775
rlwimi r4, r3, 15, 7, 11
mullw r3, r4, r5
add r2, r2, r3
srwi r3, r2, 5
andi. r3, r3, 31775
rlwimi r3, r2, 12, 22, 26
blr
Instead of:
_Trans16Bit:
.LBB_Trans16Bit_0: ; entry
slwi r2, r4, 15
rlwinm r2, r2, 0, 7, 11
andi. r4, r4, 31775
or r2, r2, r4
subfic r4, r5, 32
mullw r2, r2, r4
slwi r4, r3, 15
rlwinm r4, r4, 0, 7, 11
andi. r3, r3, 31775
or r3, r4, r3
mullw r3, r3, r5
add r2, r2, r3
srwi r3, r2, 5
andi. r3, r3, 31775
srwi r2, r2, 20
rlwimi r3, r2, 0, 22, 26
blr
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22201 91177308-0d34-0410-b5e6-96231b3b80d8
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