diff options
| -rw-r--r-- | lib/Target/PowerPC/README.txt | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index 7bc50e5..55baf8d 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -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. + +//===---------------------------------------------------------------------===// |