[AArch64][InstCombine] Bail from combining SRAD on +/-1 divisor #109274
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This fixes a crash when svdiv's third parameter is svdup_s64(1)
|
Related to #109155 |
|
@llvm/pr-subscribers-backend-aarch64 Author: Matthew Devereau (MDevereau) ChangesThis fixes a crash when svdiv's third parameter is svdup_s64(1) Full diff: https://github.com/llvm/llvm-project/pull/109274.diff 2 Files Affected:
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 649ba1ac8749f5..686503a794d7be 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -1972,7 +1972,10 @@ static std::optional<Instruction *> instCombineSVESDIV(InstCombiner &IC,
ConstantInt *SplatConstantInt = dyn_cast_or_null<ConstantInt>(SplatValue);
if (!SplatConstantInt)
return std::nullopt;
+
APInt Divisor = SplatConstantInt->getValue();
+ if (Divisor.abs().getZExtValue() == 1)
+ return std::nullopt;
if (Divisor.isPowerOf2()) {
Constant *DivisorLog2 = ConstantInt::get(Int32Ty, Divisor.logBase2());
diff --git a/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll b/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll
index 68d871355e2a23..dc134ef109fe75 100644
--- a/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll
+++ b/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll
@@ -68,6 +68,30 @@ define <vscale x 4 x i32> @sdiv_i32_not_zero(<vscale x 4 x i32> %a, <vscale x 4
ret <vscale x 4 x i32> %out
}
+; Don't instcombine to SRAD when the divisor is (+/-)1
+define <vscale x 2 x i64> @divide_by_1(<vscale x 16 x i1> %p, <vscale x 2 x i64> %a) #0 {
+; CHECK-LABEL: @divide_by_1(
+; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> [[P:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> [[TMP1]], <vscale x 2 x i64> [[A:%.*]], <vscale x 2 x i64> shufflevector (<vscale x 2 x i64> insertelement (<vscale x 2 x i64> poison, i64 1, i64 0), <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer))
+; CHECK-NEXT: ret <vscale x 2 x i64> [[TMP2]]
+;
+ %1 = call <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64 1)
+ %2 = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> %p)
+ %3 = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> %2, <vscale x 2 x i64> %a, <vscale x 2 x i64> %1)
+ ret <vscale x 2 x i64> %3
+}
+
+define <vscale x 2 x i64> @divide_by_m1(<vscale x 16 x i1> %p, <vscale x 2 x i64> %a) #0 {
+; CHECK-LABEL: @divide_by_m1(
+; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> [[P:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> [[TMP1]], <vscale x 2 x i64> [[A:%.*]], <vscale x 2 x i64> shufflevector (<vscale x 2 x i64> insertelement (<vscale x 2 x i64> poison, i64 -1, i64 0), <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer))
+; CHECK-NEXT: ret <vscale x 2 x i64> [[TMP2]]
+;
+ %1 = call <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64 -1)
+ %2 = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> %p)
+ %3 = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> %2, <vscale x 2 x i64> %a, <vscale x 2 x i64> %1)
+ ret <vscale x 2 x i64> %3
+}
declare <vscale x 4 x i32> @llvm.aarch64.sve.sdiv.nxv4i32(<vscale x 4 x i1>, <vscale x 4 x i32>, <vscale x 4 x i32>)
declare <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1>, <vscale x 2 x i64>, <vscale x 2 x i64>)
|
|
@llvm/pr-subscribers-llvm-transforms Author: Matthew Devereau (MDevereau) ChangesThis fixes a crash when svdiv's third parameter is svdup_s64(1) Full diff: https://github.com/llvm/llvm-project/pull/109274.diff 2 Files Affected:
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 649ba1ac8749f5..686503a794d7be 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -1972,7 +1972,10 @@ static std::optional<Instruction *> instCombineSVESDIV(InstCombiner &IC,
ConstantInt *SplatConstantInt = dyn_cast_or_null<ConstantInt>(SplatValue);
if (!SplatConstantInt)
return std::nullopt;
+
APInt Divisor = SplatConstantInt->getValue();
+ if (Divisor.abs().getZExtValue() == 1)
+ return std::nullopt;
if (Divisor.isPowerOf2()) {
Constant *DivisorLog2 = ConstantInt::get(Int32Ty, Divisor.logBase2());
diff --git a/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll b/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll
index 68d871355e2a23..dc134ef109fe75 100644
--- a/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll
+++ b/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-sdiv.ll
@@ -68,6 +68,30 @@ define <vscale x 4 x i32> @sdiv_i32_not_zero(<vscale x 4 x i32> %a, <vscale x 4
ret <vscale x 4 x i32> %out
}
+; Don't instcombine to SRAD when the divisor is (+/-)1
+define <vscale x 2 x i64> @divide_by_1(<vscale x 16 x i1> %p, <vscale x 2 x i64> %a) #0 {
+; CHECK-LABEL: @divide_by_1(
+; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> [[P:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> [[TMP1]], <vscale x 2 x i64> [[A:%.*]], <vscale x 2 x i64> shufflevector (<vscale x 2 x i64> insertelement (<vscale x 2 x i64> poison, i64 1, i64 0), <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer))
+; CHECK-NEXT: ret <vscale x 2 x i64> [[TMP2]]
+;
+ %1 = call <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64 1)
+ %2 = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> %p)
+ %3 = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> %2, <vscale x 2 x i64> %a, <vscale x 2 x i64> %1)
+ ret <vscale x 2 x i64> %3
+}
+
+define <vscale x 2 x i64> @divide_by_m1(<vscale x 16 x i1> %p, <vscale x 2 x i64> %a) #0 {
+; CHECK-LABEL: @divide_by_m1(
+; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> [[P:%.*]])
+; CHECK-NEXT: [[TMP2:%.*]] = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> [[TMP1]], <vscale x 2 x i64> [[A:%.*]], <vscale x 2 x i64> shufflevector (<vscale x 2 x i64> insertelement (<vscale x 2 x i64> poison, i64 -1, i64 0), <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer))
+; CHECK-NEXT: ret <vscale x 2 x i64> [[TMP2]]
+;
+ %1 = call <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64 -1)
+ %2 = call <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv2i1(<vscale x 16 x i1> %p)
+ %3 = call <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1> %2, <vscale x 2 x i64> %a, <vscale x 2 x i64> %1)
+ ret <vscale x 2 x i64> %3
+}
declare <vscale x 4 x i32> @llvm.aarch64.sve.sdiv.nxv4i32(<vscale x 4 x i1>, <vscale x 4 x i32>, <vscale x 4 x i32>)
declare <vscale x 2 x i64> @llvm.aarch64.sve.sdiv.nxv2i64(<vscale x 2 x i1>, <vscale x 2 x i64>, <vscale x 2 x i64>)
|
| APInt Divisor = SplatConstantInt->getValue(); | ||
| if (Divisor.abs().getZExtValue() == 1) | ||
| return std::nullopt; |
There was a problem hiding this comment.
For the +1 case, would it be wrong to always return Vec here?
There was a problem hiding this comment.
Yeah that makes sense. I guess the predicate wouldn't matter in that case since it would be a no-op on the whole vector
paulwalker-arm
approved these changes
Sep 20, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This fixes a crash when svdiv's third parameter is svdup_s64(1)