[llvm] r272987 - InstCombine: Reduce trunc (shl x, K) width.
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 16 21:43:22 PDT 2016
Author: arsenm
Date: Thu Jun 16 23:43:22 2016
New Revision: 272987
URL: http://llvm.org/viewvc/llvm-project?rev=272987&view=rev
Log:
InstCombine: Reduce trunc (shl x, K) width.
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
llvm/trunk/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll
llvm/trunk/test/Transforms/InstCombine/cast.ll
llvm/trunk/test/Transforms/InstCombine/icmp.ll
llvm/trunk/test/Transforms/InstCombine/trunc.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp?rev=272987&r1=272986&r2=272987&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp Thu Jun 16 23:43:22 2016
@@ -566,11 +566,30 @@ Instruction *InstCombiner::visitTrunc(Tr
// Transform "trunc (and X, cst)" -> "and (trunc X), cst" so long as the dest
// type isn't non-native.
if (Src->hasOneUse() && isa<IntegerType>(SrcTy) &&
- ShouldChangeType(SrcTy, DestTy) &&
- match(Src, m_And(m_Value(A), m_ConstantInt(Cst)))) {
- Value *NewTrunc = Builder->CreateTrunc(A, DestTy, A->getName() + ".tr");
- return BinaryOperator::CreateAnd(NewTrunc,
- ConstantExpr::getTrunc(Cst, DestTy));
+ ShouldChangeType(SrcTy, DestTy)) {
+
+ // Transform "trunc (and X, cst)" -> "and (trunc X), cst" so long as the dest
+ // type isn't non-native.
+ if (match(Src, m_And(m_Value(A), m_ConstantInt(Cst)))) {
+ Value *NewTrunc = Builder->CreateTrunc(A, DestTy, A->getName() + ".tr");
+ return BinaryOperator::CreateAnd(NewTrunc,
+ ConstantExpr::getTrunc(Cst, DestTy));
+ }
+
+ // Transform "trunc (shl X, cst)" -> "shl (trunc X), cst" so long as the dest
+ // type isn't non-native and cst < size / 2
+ if (match(Src, m_Shl(m_Value(A), m_ConstantInt(Cst)))) {
+ const unsigned Size = A->getType()->getPrimitiveSizeInBits();
+ if (Cst->getValue().ult(Size / 2)) {
+ const unsigned DstSize = DestTy->getPrimitiveSizeInBits();
+ Value *NewTrunc = Builder->CreateTrunc(A, DestTy, A->getName() + ".tr");
+
+ return BinaryOperator::CreateWithCopiedFlags(
+ Instruction::Shl, NewTrunc,
+ ConstantInt::get(DestTy, Cst->getValue().trunc(DstSize)),
+ cast<BinaryOperator>(Src));
+ }
+ }
}
if (Instruction *I = foldVecTruncToExtElt(CI, *this, DL))
Modified: llvm/trunk/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll?rev=272987&r1=272986&r2=272987&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll Thu Jun 16 23:43:22 2016
@@ -32,7 +32,8 @@ entry:
; CHECK-NOT: mul i32
%mul = mul i32 %sub, -4
; CHECK: sub i32
-; CHECK-NEXT: shl
+; CHECK-NEXT: trunc i32
+; CHECK-NEXT: shl i16
store i32 %mul, i32* %a, align 4
%tmp2 = load i32, i32* %a, align 4
%conv = trunc i32 %tmp2 to i16
Modified: llvm/trunk/test/Transforms/InstCombine/cast.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/cast.ll?rev=272987&r1=272986&r2=272987&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/cast.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/cast.ll Thu Jun 16 23:43:22 2016
@@ -980,7 +980,7 @@ define double @test72(double *%p, i32 %i
define double @test73(double *%p, i128 %i) {
; CHECK-LABEL: @test73(
; CHECK-NEXT: [[O:%.*]] = trunc i128 %i to i64
-; CHECK-NEXT: [[PP1:%.*]] = getelementptr double, double* %p, i64 [[O]]
+; CHECK-NEXT: [[PP1:%.*]] = getelementptr inbounds double, double* %p, i64 [[O]]
; CHECK-NEXT: [[L:%.*]] = load double, double* [[PP1]], align 8
; CHECK-NEXT: ret double [[L]]
;
Modified: llvm/trunk/test/Transforms/InstCombine/icmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/icmp.ll?rev=272987&r1=272986&r2=272987&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/icmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/icmp.ll Thu Jun 16 23:43:22 2016
@@ -794,9 +794,9 @@ define i1 @test60_addrspacecast_smaller(
define i1 @test60_addrspacecast_larger(i8 addrspace(1)* %foo, i32 %i, i16 %j) {
; CHECK-LABEL: @test60_addrspacecast_larger(
-; CHECK-NEXT: [[GEP1_IDX:%.*]] = shl nuw i32 %i, 2
-; CHECK-NEXT: [[TMP1:%.*]] = trunc i32 [[GEP1_IDX]] to i16
-; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i16 [[TMP1]], %j
+; CHECK-NEXT: [[TMP1:%.*]] = trunc i32 %i to i16
+; CHECK-NEXT: [[SHL:%.*]] = shl nuw i16 [[TMP1]], 2
+; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i16 [[SHL]], %j
; CHECK-NEXT: ret i1 [[TMP2]]
;
%bit = addrspacecast i8 addrspace(1)* %foo to i32 addrspace(2)*
Modified: llvm/trunk/test/Transforms/InstCombine/trunc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/trunc.ll?rev=272987&r1=272986&r2=272987&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/trunc.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/trunc.ll Thu Jun 16 23:43:22 2016
@@ -160,3 +160,112 @@ define i32 @trunc_bitcast3(<4 x i32> %v)
; CHECK-NEXT: ret i32 %ext
}
+
+; CHECK-LABEL: @trunc_shl_31_i32_i64(
+; CHECK: %val.tr = trunc i64 %val to i32
+; CHECK-NEXT: shl i32 %val.tr, 31
+define i32 @trunc_shl_31_i32_i64(i64 %val) {
+ %shl = shl i64 %val, 31
+ %trunc = trunc i64 %shl to i32
+ ret i32 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_15_i16_i64(
+; CHECK: %val.tr = trunc i64 %val to i16
+; CHECK-NEXT: shl i16 %val.tr, 15
+define i16 @trunc_shl_15_i16_i64(i64 %val) {
+ %shl = shl i64 %val, 15
+ %trunc = trunc i64 %shl to i16
+ ret i16 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_15_i16_i32(
+; CHECK: %val.tr = trunc i32 %val to i16
+; CHECK-NEXT: shl i16 %val.tr, 15
+define i16 @trunc_shl_15_i16_i32(i32 %val) {
+ %shl = shl i32 %val, 15
+ %trunc = trunc i32 %shl to i16
+ ret i16 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_7_i8_i64(
+; CHECK: %val.tr = trunc i64 %val to i8
+; CHECK-NEXT: shl i8 %val.tr, 7
+define i8 @trunc_shl_7_i8_i64(i64 %val) {
+ %shl = shl i64 %val, 7
+ %trunc = trunc i64 %shl to i8
+ ret i8 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_1_i2_i64(
+; CHECK: shl i64 %val, 1
+; CHECK-NEXT: trunc i64 %shl to i2
+define i2 @trunc_shl_1_i2_i64(i64 %val) {
+ %shl = shl i64 %val, 1
+ %trunc = trunc i64 %shl to i2
+ ret i2 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_1_i32_i64(
+; CHECK: %val.tr = trunc i64 %val to i32
+; CHECK-NEXT: shl i32 %val.tr, 1
+define i32 @trunc_shl_1_i32_i64(i64 %val) {
+ %shl = shl i64 %val, 1
+ %trunc = trunc i64 %shl to i32
+ ret i32 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_16_i32_i64(
+; CHECK: %val.tr = trunc i64 %val to i32
+; CHECK-NEXT: shl i32 %val.tr, 16
+define i32 @trunc_shl_16_i32_i64(i64 %val) {
+ %shl = shl i64 %val, 16
+ %trunc = trunc i64 %shl to i32
+ ret i32 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_33_i32_i64(
+; CHECK: ret i32 0
+define i32 @trunc_shl_33_i32_i64(i64 %val) {
+ %shl = shl i64 %val, 33
+ %trunc = trunc i64 %shl to i32
+ ret i32 %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_32_i32_i64(
+; CHECK: ret i32 0
+define i32 @trunc_shl_32_i32_i64(i64 %val) {
+ %shl = shl i64 %val, 32
+ %trunc = trunc i64 %shl to i32
+ ret i32 %trunc
+}
+
+; TODO: Should be able to handle vectors
+; CHECK-LABEL: @trunc_shl_16_v2i32_v2i64(
+; CHECK: shl <2 x i64>
+define <2 x i32> @trunc_shl_16_v2i32_v2i64(<2 x i64> %val) {
+ %shl = shl <2 x i64> %val, <i64 16, i64 16>
+ %trunc = trunc <2 x i64> %shl to <2 x i32>
+ ret <2 x i32> %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_nosplat_v2i32_v2i64(
+; CHECK: shl <2 x i64>
+define <2 x i32> @trunc_shl_nosplat_v2i32_v2i64(<2 x i64> %val) {
+ %shl = shl <2 x i64> %val, <i64 15, i64 16>
+ %trunc = trunc <2 x i64> %shl to <2 x i32>
+ ret <2 x i32> %trunc
+}
+
+; CHECK-LABEL: @trunc_shl_31_i32_i64_multi_use(
+; CHECK: shl i64 %val, 31
+; CHECK-NOT: shl i32
+; CHECK: trunc i64 %shl to i32
+; CHECK-NOT: shl i32
+define void @trunc_shl_31_i32_i64_multi_use(i64 %val, i32 addrspace(1)* %ptr0, i64 addrspace(1)* %ptr1) {
+ %shl = shl i64 %val, 31
+ %trunc = trunc i64 %shl to i32
+ store volatile i32 %trunc, i32 addrspace(1)* %ptr0
+ store volatile i64 %shl, i64 addrspace(1)* %ptr1
+ ret void
+}
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