diff options
| -rw-r--r-- | lib/Target/PowerPC/README.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index 82af6677fa..11ad35a56c 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -11,6 +11,25 @@ still a codesize win. ===-------------------------------------------------------------------------=== +Compile: + +void foo(int *P) { + if (P) *P = 0; +} + +into: + +_foo: + cmpwi cr0,r3,0 + beqlr cr0 + li r0,0 + stw r0,0(r3) + blr + +This is effectively a simple form of predication. + +===-------------------------------------------------------------------------=== + Teach the .td file to pattern match PPC::BR_COND to appropriate bc variant, so we don't have to always run the branch selector for small functions. |