[llvm] r350257 - [BDCE] Remove instructions without demanded bits
Nikita Popov via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 2 12:02:14 PST 2019
Author: nikic
Date: Wed Jan 2 12:02:14 2019
New Revision: 350257
URL: http://llvm.org/viewvc/llvm-project?rev=350257&view=rev
Log:
[BDCE] Remove instructions without demanded bits
If an instruction has no demanded bits, remove it directly during BDCE,
instead of leaving it for something else to clean up.
Differential Revision: https://reviews.llvm.org/D56185
Modified:
llvm/trunk/lib/Transforms/Scalar/BDCE.cpp
llvm/trunk/test/Transforms/BDCE/invalidate-assumptions.ll
llvm/trunk/test/Transforms/BDCE/vectors.ll
Modified: llvm/trunk/lib/Transforms/Scalar/BDCE.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/BDCE.cpp?rev=350257&r1=350256&r2=350257&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/BDCE.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/BDCE.cpp Wed Jan 2 12:02:14 2019
@@ -96,8 +96,12 @@ static bool bitTrackingDCE(Function &F,
if (I.mayHaveSideEffects() && I.use_empty())
continue;
- // Remove instructions not reached during analysis.
- if (DB.isInstructionDead(&I)) {
+ // Remove instructions that are dead, either because they were not reached
+ // during analysis or have no demanded bits.
+ if (DB.isInstructionDead(&I) ||
+ (I.getType()->isIntOrIntVectorTy() &&
+ DB.getDemandedBits(&I).isNullValue() &&
+ wouldInstructionBeTriviallyDead(&I))) {
salvageDebugInfo(I);
Worklist.push_back(&I);
I.dropAllReferences();
Modified: llvm/trunk/test/Transforms/BDCE/invalidate-assumptions.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/BDCE/invalidate-assumptions.ll?rev=350257&r1=350256&r2=350257&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/BDCE/invalidate-assumptions.ll (original)
+++ llvm/trunk/test/Transforms/BDCE/invalidate-assumptions.ll Wed Jan 2 12:02:14 2019
@@ -9,7 +9,6 @@
define i1 @PR33695(i1 %b, i8 %x) {
; CHECK-LABEL: @PR33695(
-; CHECK-NEXT: [[SETBIT:%.*]] = or i8 [[X:%.*]], 64
; CHECK-NEXT: [[LITTLE_NUMBER:%.*]] = zext i1 [[B:%.*]] to i8
; CHECK-NEXT: [[BIG_NUMBER:%.*]] = shl i8 0, 1
; CHECK-NEXT: [[SUB:%.*]] = sub i8 [[BIG_NUMBER]], [[LITTLE_NUMBER]]
@@ -29,10 +28,6 @@ define i1 @PR33695(i1 %b, i8 %x) {
define i64 @PR34037(i64 %m, i32 %r, i64 %j, i1 %b, i32 %k, i64 %p) {
; CHECK-LABEL: @PR34037(
-; CHECK-NEXT: [[CONV:%.*]] = zext i32 [[R:%.*]] to i64
-; CHECK-NEXT: [[AND:%.*]] = and i64 [[M:%.*]], 0
-; CHECK-NEXT: [[NEG:%.*]] = xor i64 0, 34359738367
-; CHECK-NEXT: [[OR:%.*]] = or i64 [[J:%.*]], 0
; CHECK-NEXT: [[SHL:%.*]] = shl i64 0, 29
; CHECK-NEXT: [[CONV1:%.*]] = select i1 [[B:%.*]], i64 7, i64 0
; CHECK-NEXT: [[SUB:%.*]] = sub i64 [[SHL]], [[CONV1]]
@@ -64,7 +59,6 @@ declare i1 @foo(i1)
define i1 @poison_on_call_user_is_ok(i1 %b, i8 %x) {
; CHECK-LABEL: @poison_on_call_user_is_ok(
-; CHECK-NEXT: [[SETBIT:%.*]] = or i8 [[X:%.*]], 64
; CHECK-NEXT: [[LITTLE_NUMBER:%.*]] = zext i1 [[B:%.*]] to i8
; CHECK-NEXT: [[BIG_NUMBER:%.*]] = shl i8 0, 1
; CHECK-NEXT: [[SUB:%.*]] = sub i8 [[BIG_NUMBER]], [[LITTLE_NUMBER]]
Modified: llvm/trunk/test/Transforms/BDCE/vectors.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/BDCE/vectors.ll?rev=350257&r1=350256&r2=350257&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/BDCE/vectors.ll (original)
+++ llvm/trunk/test/Transforms/BDCE/vectors.ll Wed Jan 2 12:02:14 2019
@@ -5,7 +5,6 @@
define <2 x i32> @test_basic(<2 x i32> %a, <2 x i32> %b) {
; CHECK-LABEL: @test_basic(
-; CHECK-NEXT: [[A2:%.*]] = add <2 x i32> [[A:%.*]], <i32 1, i32 1>
; CHECK-NEXT: [[A3:%.*]] = and <2 x i32> zeroinitializer, <i32 4, i32 4>
; CHECK-NEXT: [[B2:%.*]] = add <2 x i32> [[B:%.*]], <i32 1, i32 1>
; CHECK-NEXT: [[B3:%.*]] = and <2 x i32> [[B2]], <i32 8, i32 8>
@@ -25,7 +24,6 @@ define <2 x i32> @test_basic(<2 x i32> %
; Going vector -> scalar
define i32 @test_extractelement(<2 x i32> %a, <2 x i32> %b) {
; CHECK-LABEL: @test_extractelement(
-; CHECK-NEXT: [[A2:%.*]] = add <2 x i32> [[A:%.*]], <i32 1, i32 1>
; CHECK-NEXT: [[A3:%.*]] = and <2 x i32> zeroinitializer, <i32 4, i32 4>
; CHECK-NEXT: [[B2:%.*]] = add <2 x i32> [[B:%.*]], <i32 1, i32 1>
; CHECK-NEXT: [[B3:%.*]] = and <2 x i32> [[B2]], <i32 8, i32 8>
@@ -47,11 +45,9 @@ define i32 @test_extractelement(<2 x i32
; Going scalar -> vector
define <2 x i32> @test_insertelement(i32 %a, i32 %b) {
; CHECK-LABEL: @test_insertelement(
-; CHECK-NEXT: [[X:%.*]] = insertelement <2 x i32> undef, i32 [[A:%.*]], i32 0
-; CHECK-NEXT: [[X2:%.*]] = insertelement <2 x i32> zeroinitializer, i32 [[B:%.*]], i32 1
; CHECK-NEXT: [[X3:%.*]] = and <2 x i32> zeroinitializer, <i32 4, i32 4>
-; CHECK-NEXT: [[Y:%.*]] = insertelement <2 x i32> undef, i32 [[B]], i32 0
-; CHECK-NEXT: [[Y2:%.*]] = insertelement <2 x i32> [[Y]], i32 [[A]], i32 1
+; CHECK-NEXT: [[Y:%.*]] = insertelement <2 x i32> undef, i32 [[B:%.*]], i32 0
+; CHECK-NEXT: [[Y2:%.*]] = insertelement <2 x i32> [[Y]], i32 [[A:%.*]], i32 1
; CHECK-NEXT: [[Y3:%.*]] = and <2 x i32> [[Y2]], <i32 8, i32 8>
; CHECK-NEXT: [[Z:%.*]] = or <2 x i32> [[X3]], [[Y3]]
; CHECK-NEXT: [[U:%.*]] = ashr <2 x i32> [[Z]], <i32 3, i32 3>
@@ -91,7 +87,6 @@ define <2 x i32> @test_conversion(<2 x i
; Assumption invalidation (adapted from invalidate-assumptions.ll)
define <2 x i1> @test_assumption_invalidation(<2 x i1> %b, <2 x i8> %x) {
; CHECK-LABEL: @test_assumption_invalidation(
-; CHECK-NEXT: [[SETBIT:%.*]] = or <2 x i8> [[X:%.*]], <i8 64, i8 64>
; CHECK-NEXT: [[LITTLE_NUMBER:%.*]] = zext <2 x i1> [[B:%.*]] to <2 x i8>
; CHECK-NEXT: [[BIG_NUMBER:%.*]] = shl <2 x i8> zeroinitializer, <i8 1, i8 1>
; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i8> [[BIG_NUMBER]], [[LITTLE_NUMBER]]
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