Commit Graph

4 Commits

Author SHA1 Message Date
Tony Jiang 8e8c444d3d [PowerPC] Expand ISEL instruction into if-then-else sequence.
Generally, the ISEL is expanded into if-then-else sequence, in some
cases (like when the destination register is the same with the true
or false value register), it may just be expanded into just the if
or else sequence.

llvm-svn: 292154
2017-01-16 20:12:26 +00:00
Tony Jiang 8da139a9fd Revert "[PowerPC] Expand ISEL instruction into if-then-else sequence."
This reverts commit 1d0e0374438ca6e153844c683826ba9b82486bb1.

llvm-svn: 292131
2017-01-16 15:01:07 +00:00
Tony Jiang 7630b8c5ee [PowerPC] Expand ISEL instruction into if-then-else sequence.
Generally, the ISEL is expanded into if-then-else sequence, in some
cases (like when the destination register is the same with the true
or false value register), it may just be expanded into just the if
or else sequence.

llvm-svn: 292128
2017-01-16 14:43:12 +00:00
Hal Finkel ed6a28597b Enable early if conversion on PPC
On cores for which we know the misprediction penalty, and we have
the isel instruction, we can profitably perform early if conversion.
This enables us to replace some small branch sequences with selects
and avoid the potential stalls from mispredicting the branches.

Enabling this feature required implementing canInsertSelect and
insertSelect in PPCInstrInfo; isel code in PPCISelLowering was
refactored to use these functions as well.

llvm-svn: 178926
2013-04-05 23:29:01 +00:00