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llvm-reduce: Add volatile reduction pass
Removing volatile may help optimization passes do more to the IR. However, this will increase scheduler freedom.
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‎llvm/test/tools/llvm-reduce/reduce-volatile.ll

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; RUN: llvm-reduce --abort-on-invalid-reduction --delta-passes=volatile --test FileCheck --test-arg --check-prefixes=INTERESTING,CHECK --test-arg %s --test-arg --input-file %s -o %t
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; RUN: FileCheck -check-prefixes=RESULT,CHECK %s < %t
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; CHECK-LABEL: @load_volatile_keep(
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; INTERESTING: load volatile
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; RESULT: %op = load volatile i32,
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define i32 @load_volatile_keep(ptr %ptr) {
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%op = load volatile i32, ptr %ptr
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ret i32 %op
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}
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; CHECK-LABEL: @load_volatile_drop(
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; INTERESTING: load
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; RESULT: %op = load i32,
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define i32 @load_volatile_drop(ptr %ptr) {
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%op = load volatile i32, ptr %ptr
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ret i32 %op
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}
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; CHECK-LABEL: @store_volatile_keep(
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; INTERESTING: store volatile
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; RESULT: store volatile i32 0,
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define void @store_volatile_keep(ptr %ptr) {
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store volatile i32 0, ptr %ptr
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ret void
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}
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; CHECK-LABEL: @store_volatile_drop(
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; INTERESTING: store
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; RESULT: store i32 0,
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define void @store_volatile_drop(ptr %ptr) {
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store volatile i32 0, ptr %ptr
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ret void
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}
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; CHECK-LABEL: @atomicrmw_volatile_keep(
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; INTERESTING: atomicrmw volatile
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; RESULT: atomicrmw volatile add ptr %ptr
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define i32 @atomicrmw_volatile_keep(ptr %ptr) {
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%val = atomicrmw volatile add ptr %ptr, i32 3 seq_cst
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ret i32 %val
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}
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; CHECK-LABEL: @atomicrmw_volatile_drop(
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; INTERESTING: atomicrmw
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; RESULT: atomicrmw add ptr %ptr
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define i32 @atomicrmw_volatile_drop(ptr %ptr) {
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%val = atomicrmw volatile add ptr %ptr, i32 3 seq_cst
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ret i32 %val
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}
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; CHECK-LABEL: @cmpxchg_volatile_keep(
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; INTERESTING: cmpxchg volatile
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; RESULT: cmpxchg volatile ptr %ptr, i32 %old, i32 %in seq_cst seq_cst
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define { i32, i1 } @cmpxchg_volatile_keep(ptr %ptr, i32 %old, i32 %in) {
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%val = cmpxchg volatile ptr %ptr, i32 %old, i32 %in seq_cst seq_cst
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ret { i32, i1 } %val
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}
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; CHECK-LABEL: @cmpxchg_volatile_drop(
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; INTERESTING: cmpxchg
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; RESULT: cmpxchg ptr %ptr, i32 %old, i32 %in seq_cst seq_cst
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define { i32, i1 } @cmpxchg_volatile_drop(ptr %ptr, i32 %old, i32 %in) {
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%val = cmpxchg volatile ptr %ptr, i32 %old, i32 %in seq_cst seq_cst
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ret { i32, i1 } %val
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}
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; CHECK-LABEL: @memcpy_volatile_keep(
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; INTERESTING: i1 true
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; RESULT: call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 %size, i1 true)
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define void @memcpy_volatile_keep(ptr %dst, ptr %src, i64 %size) {
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call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 %size, i1 true)
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ret void
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}
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; CHECK-LABEL: @memcpy_volatile_drop(
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; INTERESTING: llvm.memcpy
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; RESULT: call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 %size, i1 false)
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define void @memcpy_volatile_drop(ptr %dst, ptr %src, i64 %size) {
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call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 %size, i1 true)
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ret void
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}
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; CHECK-LABEL: @memcpy_inline_volatile_keep(
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; INTERESTING: i1 true
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; RESULT: call void @llvm.memcpy.inline.p0.p0.i64(ptr %dst, ptr %src, i64 256, i1 true)
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define void @memcpy_inline_volatile_keep(ptr %dst, ptr %src) {
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call void @llvm.memcpy.inline.p0.p0.i64(ptr %dst, ptr %src, i64 256, i1 true)
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ret void
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}
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; CHECK-LABEL: @memcpy_inline_volatile_drop(
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; INTERESTING: llvm.memcpy
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; RESULT: call void @llvm.memcpy.inline.p0.p0.i64(ptr %dst, ptr %src, i64 256, i1 false)
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define void @memcpy_inline_volatile_drop(ptr %dst, ptr %src) {
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call void @llvm.memcpy.inline.p0.p0.i64(ptr %dst, ptr %src, i64 256, i1 true)
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ret void
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}
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; CHECK-LABEL: @memmove_volatile_keep(
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; INTERESTING: i1 true
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; RESULT: call void @llvm.memmove.p0.p0.i64(ptr %dst, ptr %src, i64 256, i1 true)
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define void @memmove_volatile_keep(ptr %dst, ptr %src) {
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call void @llvm.memmove.p0.p0.i64(ptr %dst, ptr %src, i64 256, i1 true)
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ret void
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}
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; CHECK-LABEL: @memmove_volatile_drop(
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; INTERESTING: llvm.memmove
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; RESULT: call void @llvm.memmove.p0.p0.i64(ptr %dst, ptr %src, i64 %size, i1 false)
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define void @memmove_volatile_drop(ptr %dst, ptr %src, i64 %size) {
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call void @llvm.memmove.p0.p0.i64(ptr %dst, ptr %src, i64 %size, i1 true)
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ret void
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}
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; CHECK-LABEL: @memset_volatile_keep(
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; INTERESTING: i1 true
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; RESULT: call void @llvm.memset.p0.i64(ptr %ptr, i8 %val, i64 %size, i1 true)
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define void @memset_volatile_keep(ptr %ptr, i8 %val, i64 %size) {
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call void @llvm.memset.p0.i64(ptr %ptr, i8 %val, i64 %size, i1 true)
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ret void
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}
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; CHECK-LABEL: @memset_volatile_drop(
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; INTERESTING: llvm.memset
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; RESULT: call void @llvm.memset.p0.i64(ptr %ptr, i8 %val, i64 %size, i1 false)
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define void @memset_volatile_drop(ptr %ptr, i8 %val, i64 %size) {
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call void @llvm.memset.p0.i64(ptr %ptr, i8 %val, i64 %size, i1 true)
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ret void
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}
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declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg)
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declare void @llvm.memmove.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg)
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declare void @llvm.memcpy.inline.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64 immarg, i1 immarg)
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declare void @llvm.memset.p0.i64(ptr noalias nocapture readonly, i8, i64, i1 immarg)

‎llvm/tools/llvm-reduce/CMakeLists.txt

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deltas/ReduceInstructionFlags.cpp
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deltas/ReduceMetadata.cpp
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deltas/ReduceModuleData.cpp
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deltas/ReduceMemoryOperations.cpp
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deltas/ReduceOperandBundles.cpp
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deltas/ReduceOpcodes.cpp
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deltas/ReduceSpecialGlobals.cpp

‎llvm/tools/llvm-reduce/DeltaManager.cpp

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#include "deltas/ReduceInstructionFlagsMIR.h"
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#include "deltas/ReduceInstructions.h"
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#include "deltas/ReduceInstructionsMIR.h"
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#include "deltas/ReduceMemoryOperations.h"
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#include "deltas/ReduceMetadata.h"
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#include "deltas/ReduceModuleData.h"
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#include "deltas/ReduceOpcodes.h"
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DELTA_PASS("attributes", reduceAttributesDeltaPass) \
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DELTA_PASS("module-data", reduceModuleDataDeltaPass) \
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DELTA_PASS("opcodes", reduceOpcodesDeltaPass) \
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DELTA_PASS("volatile", reduceVolatileInstructionsDeltaPass) \
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DELTA_PASS("instruction-flags", reduceInstructionFlagsDeltaPass) \
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} while (false)
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‎llvm/tools/llvm-reduce/deltas/ReduceMemoryOperations.cpp

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//===- ReduceOpcodes.cpp - Specialized Delta Pass -------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "ReduceMemoryOperations.h"
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#include "Delta.h"
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#include "llvm/IR/InstIterator.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/IntrinsicInst.h"
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static void removeVolatileInFunction(Oracle &O, Function &F) {
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LLVMContext &Ctx = F.getContext();
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for (Instruction &I : instructions(F)) {
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if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
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if (LI->isVolatile() && !O.shouldKeep())
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LI->setVolatile(false);
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} else if (StoreInst *SI = dyn_cast<StoreInst>(&I)) {
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if (SI->isVolatile() && !O.shouldKeep())
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SI->setVolatile(false);
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} else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&I)) {
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if (RMW->isVolatile() && !O.shouldKeep())
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RMW->setVolatile(false);
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} else if (AtomicCmpXchgInst *CmpXChg = dyn_cast<AtomicCmpXchgInst>(&I)) {
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if (CmpXChg->isVolatile() && !O.shouldKeep())
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CmpXChg->setVolatile(false);
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} else if (MemIntrinsic *MemIntrin = dyn_cast<MemIntrinsic>(&I)) {
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if (MemIntrin->isVolatile() && !O.shouldKeep())
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MemIntrin->setVolatile(ConstantInt::getFalse(Ctx));
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}
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}
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}
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static void removeVolatileInModule(Oracle &O, Module &Mod) {
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for (Function &F : Mod)
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removeVolatileInFunction(O, F);
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}
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void llvm::reduceVolatileInstructionsDeltaPass(TestRunner &Test) {
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runDeltaPass(Test, removeVolatileInModule, "Reducing Volatile Instructions");
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}

‎llvm/tools/llvm-reduce/deltas/ReduceMemoryOperations.h

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//===- ReduceMemoryOperations.h - Specialized Delta Pass --------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_TOOLS_LLVM_REDUCE_DELTAS_REDUCEMEMORYOPERATIONS_H
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#define LLVM_TOOLS_LLVM_REDUCE_DELTAS_REDUCEMEMORYOPERATIONS_H
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#include "TestRunner.h"
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namespace llvm {
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void reduceVolatileInstructionsDeltaPass(TestRunner &Test);
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} // namespace llvm
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#endif

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