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| author | Chris Lattner <sabre@nondot.org> | 2006-09-14 20:56:30 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2006-09-14 20:56:30 +0000 |
| commit | f0613e1e7cc8aae41350fb0b983ce5b43115b93a (patch) | |
| tree | 81ac5c60d07df7c9dfdd1cc0980643c1b57b4701 /lib/Target/PowerPC/README.txt | |
| parent | 516b962b5a043e4773f0655d0790e58780e3a345 (diff) | |
| download | llvm-f0613e1e7cc8aae41350fb0b983ce5b43115b93a.tar.gz llvm-f0613e1e7cc8aae41350fb0b983ce5b43115b93a.tar.bz2 llvm-f0613e1e7cc8aae41350fb0b983ce5b43115b93a.tar.xz | |
add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30377 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/PowerPC/README.txt')
| -rw-r--r-- | lib/Target/PowerPC/README.txt | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index 2c99e02e4e..b0840a5e50 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -539,3 +539,28 @@ be folded together. unsigned short G; void foo(unsigned long H) { G = H; } +===-------------------------------------------------------------------------=== + +We compile: + +unsigned test6(unsigned x) { + return ((x & 0x00FF0000) >> 16) | ((x & 0x000000FF) << 16); +} + +into: + +_test6: + lis r2, 255 + rlwinm r3, r3, 16, 0, 31 + ori r2, r2, 255 + and r3, r3, r2 + blr + +GCC gets it down to: + +_test6: + rlwinm r0,r3,16,8,15 + rlwinm r3,r3,16,24,31 + or r3,r3,r0 + blr + |