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| -rw-r--r-- | lib/Target/PowerPC/README.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index e5cf75d3be..1b05e7c4f0 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -460,3 +460,20 @@ In particular, the two compares (marked 1) could be shared by reversing one. This could be done in the dag combiner, by swapping a BR_CC when a SETCC of the same operands (but backwards) exists. In this case, this wouldn't save us anything though, because the compares still wouldn't be shared. + +===-------------------------------------------------------------------------=== + +A simple case we generate suboptimal code on: + +int test(int X) { + return X == 0 ? 32 : 0; +} + +_test: + cntlzw r2, r3 + srwi r2, r2, 5 + slwi r3, r2, 5 + blr + +The shifts should be one 'andi'. + |