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| author | Chris Lattner <sabre@nondot.org> | 2006-10-13 20:20:58 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2006-10-13 20:20:58 +0000 |
| commit | be131662c327551f13f02209ef6015ce57c23c9d (patch) | |
| tree | de8c7011d646b034656373872fe1c3c365a59c3f /llvm/lib/Target/PowerPC | |
| parent | cf56917053d2d7b90af1d0a91ad7b415cad82328 (diff) | |
| download | bcm5719-llvm-be131662c327551f13f02209ef6015ce57c23c9d.tar.gz bcm5719-llvm-be131662c327551f13f02209ef6015ce57c23c9d.zip | |
add note
llvm-svn: 30937
Diffstat (limited to 'llvm/lib/Target/PowerPC')
| -rw-r--r-- | llvm/lib/Target/PowerPC/README.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/Target/PowerPC/README.txt b/llvm/lib/Target/PowerPC/README.txt index 82af6677fa6..11ad35a56cb 100644 --- a/llvm/lib/Target/PowerPC/README.txt +++ b/llvm/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. |
