diff options
| -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 + |