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| author | Gulfem Savrun Yeniceri <gulfem@google.com> | 2024-04-04 16:36:43 +0000 |
|---|---|---|
| committer | Gulfem Savrun Yeniceri <gulfem@google.com> | 2024-04-04 16:39:31 +0000 |
| commit | be8fd86f6a57da79a4dbc8d1f4dca2e7adb1192a (patch) | |
| tree | b839f2f4f9bc0124dafacb1d1d8ea00966ae995c | |
| parent | dcc45faa30041a3378bcde4857df205382f1996a (diff) | |
| download | llvm-be8fd86f6a57da79a4dbc8d1f4dca2e7adb1192a.zip llvm-be8fd86f6a57da79a4dbc8d1f4dca2e7adb1192a.tar.gz llvm-be8fd86f6a57da79a4dbc8d1f4dca2e7adb1192a.tar.bz2 | |
Revert "[GlobalISel] Fix the infinite loop issue in `commute_int_constant_to_rhs`"
This reverts commit 1f01c580444ea2daef67f95ffc5fde2de5a37cec
because combine-commute-int-const-lhs.mir test failed in
multiple builders.
https://lab.llvm.org/buildbot/#/builders/124/builds/10375
https://luci-milo.appspot.com/ui/p/fuchsia/builders/prod/clang-linux-x64/b8751607530180046481/overview
| -rw-r--r-- | llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp | 17 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AArch64/GlobalISel/combine-commute-int-const-lhs.mir | 28 |
2 files changed, 8 insertions, 37 deletions
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp index 719209e..e53e35d 100644 --- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp +++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp @@ -6273,15 +6273,14 @@ bool CombinerHelper::matchShiftsTooBig(MachineInstr &MI) { bool CombinerHelper::matchCommuteConstantToRHS(MachineInstr &MI) { Register LHS = MI.getOperand(1).getReg(); Register RHS = MI.getOperand(2).getReg(); - if (!getIConstantVRegVal(LHS, MRI)) { - // Skip commuting if LHS is not a constant. But, LHS may be a - // G_CONSTANT_FOLD_BARRIER. If so we commute as long as we don't already - // have a constant on the RHS. - if (MRI.getVRegDef(LHS)->getOpcode() != - TargetOpcode::G_CONSTANT_FOLD_BARRIER) - return false; - } - // Commute as long as RHS is not a constant or G_CONSTANT_FOLD_BARRIER. + auto *LHSDef = MRI.getVRegDef(LHS); + if (getIConstantVRegVal(LHS, MRI).has_value()) + return true; + + // LHS may be a G_CONSTANT_FOLD_BARRIER. If so we commute + // as long as we don't already have a constant on the RHS. + if (LHSDef->getOpcode() != TargetOpcode::G_CONSTANT_FOLD_BARRIER) + return false; return MRI.getVRegDef(RHS)->getOpcode() != TargetOpcode::G_CONSTANT_FOLD_BARRIER && !getIConstantVRegVal(RHS, MRI); diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/combine-commute-int-const-lhs.mir b/llvm/test/CodeGen/AArch64/GlobalISel/combine-commute-int-const-lhs.mir deleted file mode 100644 index b145a6d..0000000 --- a/llvm/test/CodeGen/AArch64/GlobalISel/combine-commute-int-const-lhs.mir +++ /dev/null @@ -1,28 +0,0 @@ -# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 4 -# RUN: llc -mtriple aarch64 -run-pass=aarch64-prelegalizer-combiner %s -o - \ -# RUN: --aarch64prelegalizercombiner-disable-rule=constant_fold_binop | FileCheck %s - -# `constant_fold_binop` is disabled to trigger the infinite loop in `commute_int_constant_to_rhs`. - ---- -name: add -tracksRegLiveness: true -body: | - bb.0: - liveins: $s0 - - ; CHECK-LABEL: name: add - ; CHECK: liveins: $s0 - ; CHECK-NEXT: {{ $}} - ; CHECK-NEXT: %c0:_(s32) = G_CONSTANT i32 1 - ; CHECK-NEXT: %c1:_(s32) = G_CONSTANT i32 2 - ; CHECK-NEXT: %add:_(s32) = G_ADD %c0, %c1 - ; CHECK-NEXT: $s0 = COPY %add(s32) - ; CHECK-NEXT: RET_ReallyLR - %c0:_(s32) = G_CONSTANT i32 1 - %c1:_(s32) = G_CONSTANT i32 2 - %add:_(s32) = G_ADD %c0, %c1 - $s0 = COPY %add - RET_ReallyLR - -... |