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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30937 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-10-13 20:20:58 +00:00
parent 594f4c69e6
commit 6a250ecc99
1 changed files with 19 additions and 0 deletions
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19
lib/Target/PowerPC/README.txt
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@ -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 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. we don't have to always run the branch selector for small functions.