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Diffstat (limited to 'llvm/lib/Target/PowerPC/README.txt')
| -rw-r--r-- | llvm/lib/Target/PowerPC/README.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/Target/PowerPC/README.txt b/llvm/lib/Target/PowerPC/README.txt index d77d20d85ad..468d974a278 100644 --- a/llvm/lib/Target/PowerPC/README.txt +++ b/llvm/lib/Target/PowerPC/README.txt @@ -448,3 +448,22 @@ LBB1_2: blr noticed in 2005-05-11-Popcount-ffs-fls.c. + + +===-------------------------------------------------------------------------=== + +We should custom expand setcc instead of pretending that we have it. That +would allow us to expose the access of the crbit after the mfcr, allowing +that access to be trivially folded into other ops. A simple example: + +int foo(int a, int b) { return (a < b) << 4; } + +compiles into: + +_foo: + cmpw cr7, r3, r4 + mfcr r2, 1 + rlwinm r2, r2, 29, 31, 31 + slwi r3, r2, 4 + blr + |
