Commit Graph

2 Commits

Author SHA1 Message Date
Abinav Puthan Purayil 078da26b1c [AMDGPU] Check for unneeded shift mask in shift PatFrags.
The existing constrained shift PatFrags only dealt with masked shift
from OpenCL front-ends. This change copies the
X86DAGToDAGISel::isUnneededShiftMask() function to AMDGPU and uses it in
the shift PatFrag predicates.

Differential Revision: https://reviews.llvm.org/D113448
2021-11-24 10:53:12 +05:30
Abinav Puthan Purayil 61e3b9fefe [AMDGPU] Add constrained shift pattern matches.
The motivation for this is due to clang's conformance to
https://www.khronos.org/registry/OpenCL/specs/3.0-unified/html/OpenCL_C.html#operators-shift
which makes clang emit (<shift> a, (and b, <width> - 1)) for `a <shift> b`
in OpenCL where a is an int of bit width <width>.

Differential revision: https://reviews.llvm.org/D110231
2021-10-26 19:07:19 +05:30