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| author | Chris Lattner <sabre@nondot.org> | 2010-09-19 00:34:58 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-09-19 00:34:58 +0000 |
| commit | 2e040ebe19d2fe6ae12f885b0dea426fb3b8a847 (patch) | |
| tree | ccbd7d4cf1083227a2afe207d52a468cd694abbd | |
| parent | b737bac6ed49312f355cf915bb642123776b7945 (diff) | |
| download | bcm5719-llvm-2e040ebe19d2fe6ae12f885b0dea426fb3b8a847.tar.gz bcm5719-llvm-2e040ebe19d2fe6ae12f885b0dea426fb3b8a847.zip | |
add a readme.
llvm-svn: 114303
| -rw-r--r-- | llvm/lib/Target/PowerPC/README.txt | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/llvm/lib/Target/PowerPC/README.txt b/llvm/lib/Target/PowerPC/README.txt index 3465779e344..4c80225d041 100644 --- a/llvm/lib/Target/PowerPC/README.txt +++ b/llvm/lib/Target/PowerPC/README.txt @@ -37,6 +37,31 @@ _f3: ori r3, r2, 65535 blr +===-------------------------------------------------------------------------=== + +This code: + +unsigned add32carry(unsigned sum, unsigned x) { + unsigned z = sum + x; + if (sum + x < x) + z++; + return z; +} + +Should compile to something like: + + addc r3,r3,r4 + addze r3,r3 + +instead we get: + + add r3, r4, r3 + cmplw cr7, r3, r4 + mfcr r4 ; 1 + rlwinm r4, r4, 29, 31, 31 + add r3, r3, r4 + +Ick. ===-------------------------------------------------------------------------=== |
