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Revert "[flang] Enable alias tags pass by default (#73111)" (#73821)
This reverts commit caba031. Serious performance regressions were reported by @vzakhari #58303 (comment) Fixing this doesn't look quick so I will revert for now.
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8 files changed

+21
-60
lines changed

8 files changed

+21
-60
lines changed

‎clang/lib/Driver/ToolChains/Flang.cpp

Lines changed: 0 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -142,26 +142,6 @@ void Flang::addCodegenOptions(const ArgList &Args,
142142
if (shouldLoopVersion(Args))
143143
CmdArgs.push_back("-fversion-loops-for-stride");
144144

145-
Arg *aliasAnalysis = Args.getLastArg(options::OPT_falias_analysis,
146-
options::OPT_fno_alias_analysis);
147-
// only pass on the argument if it does not match that implied by the
148-
// optimization level: so if optimization is requested, only forward
149-
// -fno-alias-analysis. If optimization is not requested, only forward
150-
// -falias-analysis.
151-
Arg *optLevel =
152-
Args.getLastArg(options::OPT_Ofast, options::OPT_O, options::OPT_O4);
153-
if (aliasAnalysis) {
154-
bool faliasAnalysis =
155-
aliasAnalysis->getOption().matches(options::OPT_falias_analysis);
156-
if (optLevel && !faliasAnalysis) {
157-
CmdArgs.push_back("-fno-alias-analysis");
158-
} else {
159-
if (faliasAnalysis)
160-
// requested alias analysis but no optimization enabled
161-
CmdArgs.push_back("-falias-analysis");
162-
}
163-
}
164-
165145
Args.addAllArgs(CmdArgs, {options::OPT_flang_experimental_hlfir,
166146
options::OPT_flang_deprecated_no_hlfir,
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options::OPT_flang_experimental_polymorphism,

‎flang/include/flang/Tools/CLOptions.inc

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -158,10 +158,10 @@ inline void addDebugFoundationPass(mlir::PassManager &pm) {
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}
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160160
inline void addFIRToLLVMPass(
161-
mlir::PassManager &pm, const MLIRToLLVMPassPipelineConfig &config) {
161+
mlir::PassManager &pm, llvm::OptimizationLevel optLevel = defaultOptLevel) {
162162
fir::FIRToLLVMPassOptions options;
163163
options.ignoreMissingTypeDescriptors = ignoreMissingTypeDescriptors;
164-
options.applyTBAA = config.AliasAnalysis;
164+
options.applyTBAA = optLevel.isOptimizingForSpeed();
165165
options.forceUnifiedTBAATree = useOldAliasTags;
166166
addPassConditionally(pm, disableFirToLlvmIr,
167167
[&]() { return fir::createFIRToLLVMPass(options); });
@@ -311,7 +311,7 @@ inline void createDefaultFIRCodeGenPassPipeline(
311311
if (config.VScaleMin != 0)
312312
pm.addPass(fir::createVScaleAttrPass({config.VScaleMin, config.VScaleMax}));
313313

314-
fir::addFIRToLLVMPass(pm, config);
314+
fir::addFIRToLLVMPass(pm, config.OptLevel);
315315
}
316316

317317
/// Create a pass pipeline for lowering from MLIR to LLVM IR

‎flang/lib/Frontend/CompilerInvocation.cpp

Lines changed: 4 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -242,12 +242,10 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
242242
clang::driver::options::OPT_fno_loop_versioning, false))
243243
opts.LoopVersioning = 1;
244244

245-
opts.AliasAnalysis = opts.OptimizationLevel > 0;
246-
if (auto *arg =
247-
args.getLastArg(clang::driver::options::OPT_falias_analysis,
248-
clang::driver::options::OPT_fno_alias_analysis))
249-
opts.AliasAnalysis =
250-
arg->getOption().matches(clang::driver::options::OPT_falias_analysis);
245+
opts.AliasAnalysis =
246+
args.hasFlag(clang::driver::options::OPT_falias_analysis,
247+
clang::driver::options::OPT_fno_alias_analysis,
248+
/*default=*/false);
251249

252250
for (auto *a : args.filtered(clang::driver::options::OPT_fpass_plugin_EQ))
253251
opts.LLVMPassPlugins.push_back(a->getValue());

‎flang/test/Driver/falias-analysis.f90

Lines changed: 1 addition & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -2,26 +2,12 @@
22
! See flang/test/Fir/tbaa-codegen.fir for a test that the output is correct
33

44
! RUN: %flang -c -emit-llvm -falias-analysis %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
5-
! RUN: %flang -c -emit-llvm -Ofast %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
6-
! RUN: %flang -c -emit-llvm -O3 %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
7-
! RUN: %flang -c -emit-llvm -O2 %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
8-
! RUN: %flang -c -emit-llvm -O1 %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
9-
10-
! RUN: %flang -c -emit-llvm -O0 %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
11-
! RUN: %flang -c -emit-llvm -Ofast -fno-alias-analysis %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
12-
! RUN: %flang -c -emit-llvm -fno-alias-analysis -Ofast %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
13-
! RUN: %flang -c -emit-llvm %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
145
! RUN: %flang -c -emit-llvm -falias-analysis -fno-alias-analysis %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
6+
! RUN: %flang -c -emit-llvm %s -o - | llvm-dis | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
157

168
! RUN: %flang -fc1 -emit-llvm -falias-analysis %s -o - | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
17-
! RUN: %flang -fc1 -emit-llvm -O3 %s -o - | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
18-
! RUN: %flang -fc1 -emit-llvm -O2 %s -o - | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
19-
! RUN: %flang -fc1 -emit-llvm -O1 %s -o - | FileCheck %s --check-prefix=CHECK-AA --check-prefix=CHECK-ALL
20-
21-
! RUN: %flang -fc1 -emit-llvm -O0 %s -o - | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
229
! RUN: %flang -fc1 -emit-llvm -falias-analysis -fno-alias-analysis %s -o - | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
2310
! RUN: %flang -fc1 -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
24-
! RUN: %flang -fc1 -emit-llvm -O3 -fno-alias-analysis %s -o - | FileCheck %s --check-prefix=CHECK-NOAA --check-prefix=CHECK-ALL
2511

2612
subroutine simple(a)
2713
integer, intent(inout) :: a(:)

‎flang/test/Driver/mlir-pass-pipeline.f90

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -51,8 +51,6 @@
5151

5252
! ALL-NEXT: 'func.func' Pipeline
5353
! ALL-NEXT: PolymorphicOpConversion
54-
! O2-NEXT: AddAliasTags
55-
! O2-NEXT: 'func.func' Pipeline
5654
! ALL-NEXT: CFGConversion
5755

5856
! ALL-NEXT: SCFToControlFlow

‎flang/test/Driver/optimization-remark.f90

Lines changed: 13 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -41,24 +41,28 @@
4141
! Once we start filtering, this is reduced to 1 one of the loop passes.
4242

4343
! PASS-REGEX-LOOP-ONLY-NOT: optimization-remark.f90:77:7: remark: hoisting load [-Rpass=licm]
44-
! PASS-REGEX-LOOP-ONLY: optimization-remark.f90:79:5: remark: Loop deleted because it is invariant [-Rpass=loop-delete]
44+
! PASS-REGEX-LOOP-ONLY: optimization-remark.f90:83:5: remark: Loop deleted because it is invariant [-Rpass=loop-delete]
4545

4646
! MISSED-REGEX-LOOP-ONLY-NOT: optimization-remark.f90:77:7: remark: failed to hoist load with loop-invariant address because load is conditionally executed [-Rpass-missed=licm]
47-
! MISSED-REGEX-LOOP-ONLY: optimization-remark.f90:72:4: remark: loop not vectorized [-Rpass-missed=loop-vectorize]
47+
! MISSED-REGEX-LOOP-ONLY: optimization-remark.f90:76:4: remark: loop not vectorized [-Rpass-missed=loop-vectorize]
4848

4949

50-
! ANALYSIS-REGEX-LOOP-ONLY: optimization-remark.f90:73:7: remark: loop not vectorized: cannot identify array bounds [-Rpass-analysis=loop-vectorize]
50+
! ANALYSIS-REGEX-LOOP-ONLY: optimization-remark.f90:79:7: remark: loop not vectorized: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
51+
! ANALYSIS-REGEX-LOOP-ONLY: Unknown data dependence. Memory location is the same as accessed at optimization-remark.f90:78:7 [-Rpass-analysis=loop-vectorize]
5152
! ANALYSIS-REGEX-LOOP-ONLY-NOT: remark: {{.*}}: IR instruction count changed from {{[0-9]+}} to {{[0-9]+}}; Delta: {{-?[0-9]+}} [-Rpass-analysis=size-info]
5253

53-
! PASS: optimization-remark.f90:79:5: remark: Loop deleted because it is invariant [-Rpass=loop-delete]
54+
! PASS: optimization-remark.f90:77:7: remark: hoisting load [-Rpass=licm]
55+
! PASS: optimization-remark.f90:83:5: remark: Loop deleted because it is invariant [-Rpass=loop-delete]
5456

55-
! MISSED: optimization-remark.f90:73:7: remark: failed to move load with loop-invariant address because the loop may invalidate its value [-Rpass-missed=licm]
56-
! MISSED: optimization-remark.f90:72:4: remark: loop not vectorized [-Rpass-missed=loop-vectorize]
57-
! MISSED-NOT: optimization-remark.f90:75:7: remark: loop not vectorized: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
57+
! MISSED: optimization-remark.f90:77:7: remark: failed to hoist load with loop-invariant address because load is conditionally executed [-Rpass-missed=licm]
58+
! MISSED: optimization-remark.f90:76:4: remark: loop not vectorized [-Rpass-missed=loop-vectorize]
59+
! MISSED-NOT: optimization-remark.f90:79:7: remark: loop not vectorized: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
5860
! MISSED-NOT: Unknown data dependence. Memory location is the same as accessed at optimization-remark.f90:78:7 [-Rpass-analysis=loop-vectorize]
5961

60-
! ANALYSIS: optimization-remark.f90:74:7: remark: loop not vectorized: unsafe dependent memory operations in loop.
61-
! ANALYSIS: remark: {{.*}} instructions in function [-Rpass-analysis=asm-printer]
62+
! ANALYSIS: optimization-remark.f90:79:7: remark: loop not vectorized: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
63+
! ANALYSIS: Unknown data dependence. Memory location is the same as accessed at optimization-remark.f90:78:7 [-Rpass-analysis=loop-vectorize]
64+
! ANALYSIS: remark: {{.*}}: IR instruction count changed from {{[0-9]+}} to {{[0-9]+}}; Delta: {{-?[0-9]+}} [-Rpass-analysis=size-info]
65+
! ANALYSIS-NOT: optimization-remark.f90:77:7: remark: failed to hoist load with loop-invariant address because load is conditionally executed [-Rpass-missed=licm]
6266

6367
subroutine swap_real(a1, a2)
6468
implicit none

‎flang/test/Fir/basic-program.fir

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -57,10 +57,6 @@ func.func @_QQmain() {
5757

5858
// PASSES-NEXT: 'func.func' Pipeline
5959
// PASSES-NEXT: PolymorphicOpConversion
60-
61-
// PASSES-NEXT: AddAliasTags
62-
63-
// PASSES-NEXT: 'func.func' Pipeline
6460
// PASSES-NEXT: CFGConversion
6561

6662
// PASSES-NEXT: SCFToControlFlow

‎flang/tools/tco/tco.cpp

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -120,7 +120,6 @@ compileFIR(const mlir::PassPipelineCLParser &passPipeline) {
120120
return mlir::failure();
121121
} else {
122122
MLIRToLLVMPassPipelineConfig config(llvm::OptimizationLevel::O2);
123-
config.AliasAnalysis = true; // enabled when optimizing for speed
124123
if (codeGenLLVM) {
125124
// Run only CodeGen passes.
126125
fir::createDefaultFIRCodeGenPassPipeline(pm, config);

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