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Differential D76976

[NewGVN] Make NewGVN aware of aligned_alloc
ClosedPublic

Authored by bondhugula on Mar 28 2020, 12:37 AM.

Details

Reviewers
jdoerfert
xbolva00
Commits
rG6ee11c3b0f36: [NewGVN] Make NewGVN aware of aligned_alloc
Summary

Make the New GVN pass aware of aligned_alloc.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Depends on D76975.

Diff Detail

Event Timeline

bondhugula created this revision.Mar 28 2020, 12:37 AM
Herald added a project: Restricted Project. · View Herald TranscriptMar 28 2020, 12:37 AM
Herald added subscribers: llvm-commits, hiraditya, Prazek. · View Herald Transcript
bondhugula updated this revision to Diff 253320.Mar 28 2020, 1:33 AM

Add test case

Harbormaster failed remote builds in B50782: Diff 253307!Mar 28 2020, 1:35 AM
Harbormaster failed remote builds in B50793: Diff 253320!Mar 28 2020, 2:10 AM
xbolva00 accepted this revision.Mar 29 2020, 9:38 AM
This revision is now accepted and ready to land.Mar 29 2020, 9:38 AM
fhahn added a subscriber: fhahn.Mar 29 2020, 10:22 AM

Please prefix the commit message with something like [NewGVN]

bondhugula added a comment.Mar 29 2020, 10:53 AM
In D76976#1948652, @fhahn wrote:

Please prefix the commit message with something like [NewGVN]

Even if NewGVN already appears in the title? Thanks.

bondhugula mentioned this in D71521: Introduce support for lib function aligned_alloc.Mar 29 2020, 10:05 PM
bondhugula retitled this revision from Make NewGVN aware of aligned_alloc to [NewGVN] Make NewGVN aware of aligned_alloc.Mar 31 2020, 10:49 AM
Closed by commit rG6ee11c3b0f36: [NewGVN] Make NewGVN aware of aligned_alloc (authored by bondhugula). · Explain WhyApr 1 2020, 10:59 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
llvm/
lib/
Transforms/
Scalar/
3 lines
test/
Transforms/
NewGVN/
25 lines

Diff 254257

llvm/lib/Transforms/Scalar/NewGVN.cpp

Show First 20 Lines • Show All 1,464 Lines • ▼ Show 20 LinesNewGVN::performSymbolicLoadCoercion(Type *LoadType, Value *LoadPtr,
// by the dependent instruction. // by the dependent instruction.
if (LoadPtr != lookupOperandLeader(DepInst) && if (LoadPtr != lookupOperandLeader(DepInst) &&
!AA->isMustAlias(LoadPtr, DepInst)) !AA->isMustAlias(LoadPtr, DepInst))
return nullptr; return nullptr;
// If this load really doesn't depend on anything, then we must be loading an // If this load really doesn't depend on anything, then we must be loading an
// undef value. This can happen when loading for a fresh allocation with no // undef value. This can happen when loading for a fresh allocation with no
// intervening stores, for example. Note that this is only true in the case // intervening stores, for example. Note that this is only true in the case
// that the result of the allocation is pointer equal to the load ptr. // that the result of the allocation is pointer equal to the load ptr.
if (isa<AllocaInst>(DepInst) || isMallocLikeFn(DepInst, TLI)) { if (isa<AllocaInst>(DepInst) || isMallocLikeFn(DepInst, TLI) ||
isAlignedAllocLikeFn(DepInst, TLI)) {
return createConstantExpression(UndefValue::get(LoadType)); return createConstantExpression(UndefValue::get(LoadType));
} }
// If this load occurs either right after a lifetime begin, // If this load occurs either right after a lifetime begin,
// then the loaded value is undefined. // then the loaded value is undefined.
else if (auto *II = dyn_cast<IntrinsicInst>(DepInst)) { else if (auto *II = dyn_cast<IntrinsicInst>(DepInst)) {
if (II->getIntrinsicID() == Intrinsic::lifetime_start) if (II->getIntrinsicID() == Intrinsic::lifetime_start)
return createConstantExpression(UndefValue::get(LoadType)); return createConstantExpression(UndefValue::get(LoadType));
} }
▲ Show 20 Lines • Show All 2,765 Lines • Show Last 20 Lines

llvm/test/Transforms/NewGVN/malloc-load-removal.ll

Show First 20 Lines • Show All 48 Lines • ▼ Show 20 Lines
; CHECK-LABEL: @test2( ; CHECK-LABEL: @test2(
; CHECK-NOT: load ; CHECK-NOT: load
; CHECK-NOT: icmp ; CHECK-NOT: icmp
; CHECK_NO_LIBCALLS-LABEL: @test2( ; CHECK_NO_LIBCALLS-LABEL: @test2(
; CHECK_NO_LIBCALLS: load ; CHECK_NO_LIBCALLS: load
; CHECK_NO_LIBCALLS: icmp ; CHECK_NO_LIBCALLS: icmp
} }
declare i8* @aligned_alloc(i64, i64) nounwind
define noalias i8* @test3() nounwind uwtable ssp {
entry:
%call = tail call i8* @aligned_alloc(i64 256, i64 32) nounwind
%0 = load i8, i8* %call, align 32
%tobool = icmp eq i8 %0, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
store i8 0, i8* %call, align 1
br label %if.end
if.end: ; preds = %if.then, %entry
ret i8* %call
; CHECK-LABEL: @test3(
; CHECK-NOT: load
; CHECK-NOT: icmp
; CHECK_NO_LIBCALLS-LABEL: @test3(
; CHECK_NO_LIBCALLS: load
; CHECK_NO_LIBCALLS: icmp
}