Commit Graph

2 Commits

Author SHA1 Message Date
Ehsan Amiri a538b0f023 Adding -verify-machineinstrs option to PowerPC tests
Currently we have a number of tests that fail with -verify-machineinstrs.
To detect this cases earlier we add the option to the testcases with the
exception of tests that will currently fail with this option. PR 27456 keeps
track of this failures.

No code review, as discussed with Hal Finkel.

llvm-svn: 277624
2016-08-03 18:17:35 +00:00
Hal Finkel 22498fa6e3 PPC: Optimize rldicl generation for masked shifts
Masking operations (where only some number of the low bits are being kept) are
selected to rldicl(x, 0, mb). If x is a logical right shift (which would become
rldicl(y, 64-n, n)), we might be able to fold the two instructions together:

  rldicl(rldicl(x, 64-n, n), 0, mb) -> rldicl(x, 64-n, mb) for n <= mb

The right shift is really a left rotate followed by a mask, and if the explicit
mask is a more-restrictive sub-mask of the mask implied by the shift, only one
rldicl is needed.

llvm-svn: 195185
2013-11-20 01:10:15 +00:00