[PATCH] D71829: [PowerPC] Exploit the rlwinm instructions for "and" with constant.
ChenZheng via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Wed Dec 25 19:56:35 PST 2019
shchenz added inline comments.
================
Comment at: llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp:4456
+ // using "and" instruction. Try to exploit it with rotate mask instructions.
+ if (isRunOfOnes64(Imm64, MB, ME)) {
+ if (MB >= 32 && MB <= ME) {
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Seems if you only consider MB>=32 && MB<=ME case, i think current isRunOfOnes for type i32 should match your requirement? Before call isRunOfOnes() check whether Imm64 can be represented by i32?
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Comment at: llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp:4457
+ if (isRunOfOnes64(Imm64, MB, ME)) {
+ if (MB >= 32 && MB <= ME) {
+ // MB ME
----------------
for ` and reg, 0xffffffffffff00ffULL`, it should be replaced by one single rlwinm instruction, seems it is not handled here?
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D71829/new/
https://reviews.llvm.org/D71829
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