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llvm-svn: 47830
This commit is contained in:
Chris Lattner 2008-03-02 19:27:34 +00:00
parent a70df9e2ee
commit 6b0a189225
1 changed files with 39 additions and 0 deletions
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39
llvm/lib/Target/PowerPC/README.txt
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@ -714,3 +714,42 @@ GCC compiles this into:
which is more efficient and can use mfocr. See PR642 for some more context.
//===---------------------------------------------------------------------===//
void foo(float *data, float d) {
long i;
for (i = 0; i < 8000; i++)
data[i] = d;
}
void foo2(float *data, float d) {
long i;
data--;
for (i = 0; i < 8000; i++) {
data[1] = d;
data++;
}
}
These compile to:
_foo:
li r2, 0
LBB1_1: ; bb
addi r4, r2, 4
stfsx f1, r3, r2
cmplwi cr0, r4, 32000
mr r2, r4
bne cr0, LBB1_1 ; bb
blr
_foo2:
li r2, 0
LBB2_1: ; bb
addi r4, r2, 4
stfsx f1, r3, r2
cmplwi cr0, r4, 32000
mr r2, r4
bne cr0, LBB2_1 ; bb
blr
The 'mr' could be eliminated to folding the add into the cmp better.
//===---------------------------------------------------------------------===//