[DAG] Extend the computeOverflowForSignedSub/computeOverflowForUnsignedSub implementations with ConstantRange #67890
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
Member
elhewaty
commented
Sep 30, 2023
elhewaty
commented
- Add tests for computeOverflowFor*Sub functions
- extend the computeOverflowForSignedSub/computeOverflowForUnsignedSub implementations with ConstantRange
…implementations with ConstantRange
|
@llvm/pr-subscribers-llvm-selectiondag @llvm/pr-subscribers-backend-x86 Changes
Full diff: https://github.com/llvm/llvm-project/pull/67890.diff 3 Files Affected:
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index cd21af770e1a4d9..0a61920b7c079ba 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4091,8 +4091,11 @@ SelectionDAG::computeOverflowForSignedSub(SDValue N0, SDValue N1) const {
if (ComputeNumSignBits(N0) > 1 && ComputeNumSignBits(N1) > 1)
return OFK_Never;
- // TODO: Add ConstantRange::signedSubMayOverflow handling.
- return OFK_Sometime;
+ KnownBits N0Known = computeKnownBits(N0);
+ KnownBits N1Known = computeKnownBits(N1);
+ ConstantRange N0Range = ConstantRange::fromKnownBits(N0Known, true);
+ ConstantRange N1Range = ConstantRange::fromKnownBits(N1Known, true);
+ return mapOverflowResult(N0Range.signedSubMayOverflow(N1Range));
}
SelectionDAG::OverflowKind
@@ -4101,8 +4104,11 @@ SelectionDAG::computeOverflowForUnsignedSub(SDValue N0, SDValue N1) const {
if (isNullConstant(N1))
return OFK_Never;
- // TODO: Add ConstantRange::unsignedSubMayOverflow handling.
- return OFK_Sometime;
+ KnownBits N0Known = computeKnownBits(N0);
+ KnownBits N1Known = computeKnownBits(N1);
+ ConstantRange N0Range = ConstantRange::fromKnownBits(N0Known, false);
+ ConstantRange N1Range = ConstantRange::fromKnownBits(N1Known, false);
+ return mapOverflowResult(N0Range.unsignedSubMayOverflow(N1Range));
}
SelectionDAG::OverflowKind
diff --git a/llvm/test/CodeGen/X86/combine-subo.ll b/llvm/test/CodeGen/X86/combine-subo.ll
index 6965f6d7af27b53..99f26525d49e5b5 100644
--- a/llvm/test/CodeGen/X86/combine-subo.ll
+++ b/llvm/test/CodeGen/X86/combine-subo.ll
@@ -4,9 +4,14 @@
declare {i32, i1} @llvm.ssub.with.overflow.i32(i32, i32) nounwind readnone
declare {i32, i1} @llvm.usub.with.overflow.i32(i32, i32) nounwind readnone
+declare { i8, i1 } @llvm.ssub.with.overflow.i8(i8, i8) nounwind readnone
+declare { i8, i1 } @llvm.usub.with.overflow.i8(i8, i8) nounwind readnone
+
declare {<4 x i32>, <4 x i1>} @llvm.ssub.with.overflow.v4i32(<4 x i32>, <4 x i32>) nounwind readnone
declare {<4 x i32>, <4 x i1>} @llvm.usub.with.overflow.v4i32(<4 x i32>, <4 x i32>) nounwind readnone
+declare { <4 x i8>, <4 x i1> } @llvm.ssub.with.overflow.v4i8(<4 x i8>, <4 x i8>) nounwind readnone
+declare { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8> , <4 x i8>) nounwind readnone
; fold (ssub x, 0) -> x
define i32 @combine_ssub_zero(i32 %a0, i32 %a1) {
@@ -148,3 +153,79 @@ define <4 x i32> @combine_vec_usub_negone(<4 x i32> %a0, <4 x i32> %a1) {
%4 = select <4 x i1> %3, <4 x i32> %a1, <4 x i32> %2
ret <4 x i32> %4
}
+
+define { i32, i1 } @combine_usub_nuw(i32 %a, i32 %b) {
+; CHECK-LABEL: combine_usub_nuw:
+; CHECK: # %bb.0:
+; CHECK-NEXT: movl %edi, %eax
+; CHECK-NEXT: orl $-2147483648, %eax # imm = 0x80000000
+; CHECK-NEXT: andl $2147483647, %esi # imm = 0x7FFFFFFF
+; CHECK-NEXT: subl %esi, %eax
+; CHECK-NEXT: xorl %edx, %edx
+; CHECK-NEXT: retq
+ %aa = or i32 %a, 2147483648
+ %bb = and i32 %b, 2147483647
+ %x = call { i32, i1 } @llvm.usub.with.overflow.i32(i32 %aa, i32 %bb)
+ ret { i32, i1 } %x
+}
+
+define { i8, i1 } @usub_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: usub_always_overflow:
+; CHECK: # %bb.0:
+; CHECK-NEXT: orb $64, %dil
+; CHECK-NEXT: movb $63, %al
+; CHECK-NEXT: subb %dil, %al
+; CHECK-NEXT: setb %dl
+; CHECK-NEXT: retq
+ %y = or i8 %x, 64
+ %a = call { i8, i1 } @llvm.usub.with.overflow.i8(i8 63, i8 %y)
+ ret { i8, i1 } %a
+}
+
+define { i8, i1 } @ssub_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: ssub_always_overflow:
+; CHECK: # %bb.0:
+; CHECK-NEXT: cmpb $30, %dil
+; CHECK-NEXT: movl $29, %ecx
+; CHECK-NEXT: cmovgel %edi, %ecx
+; CHECK-NEXT: movb $-100, %al
+; CHECK-NEXT: subb %cl, %al
+; CHECK-NEXT: seto %dl
+; CHECK-NEXT: retq
+ %c = icmp sgt i8 %x, 29
+ %y = select i1 %c, i8 %x, i8 29
+ %a = call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 -100, i8 %y)
+ ret { i8, i1 } %a
+}
+
+define { <4 x i8>, <4 x i1> } @always_usub_const_vector() nounwind {
+; SSE-LABEL: always_usub_const_vector:
+; SSE: # %bb.0:
+; SSE-NEXT: pcmpeqd %xmm0, %xmm0
+; SSE-NEXT: pcmpeqd %xmm1, %xmm1
+; SSE-NEXT: retq
+;
+; AVX-LABEL: always_usub_const_vector:
+; AVX: # %bb.0:
+; AVX-NEXT: vpcmpeqd %xmm0, %xmm0, %xmm0
+; AVX-NEXT: vpcmpeqd %xmm1, %xmm1, %xmm1
+; AVX-NEXT: retq
+ %x = call { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8> <i8 0, i8 0, i8 0, i8 0>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
+ ret { <4 x i8>, <4 x i1> } %x
+}
+
+define { <4 x i8>, <4 x i1> } @never_usub_const_vector() nounwind {
+; SSE-LABEL: never_usub_const_vector:
+; SSE: # %bb.0:
+; SSE-NEXT: movaps {{.*#+}} xmm0 = <127,255,0,254,u,u,u,u,u,u,u,u,u,u,u,u>
+; SSE-NEXT: xorps %xmm1, %xmm1
+; SSE-NEXT: retq
+;
+; AVX-LABEL: never_usub_const_vector:
+; AVX: # %bb.0:
+; AVX-NEXT: vbroadcastss {{.*#+}} xmm0 = [127,255,0,254,127,255,0,254,127,255,0,254,127,255,0,254]
+; AVX-NEXT: vxorps %xmm1, %xmm1, %xmm1
+; AVX-NEXT: retq
+ %x = call { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8> <i8 255, i8 255, i8 255, i8 255>, <4 x i8> <i8 128, i8 0, i8 255, i8 1>)
+ ret { <4 x i8>, <4 x i1> } %x
+}
diff --git a/llvm/test/CodeGen/X86/or-with-overflow.ll b/llvm/test/CodeGen/X86/or-with-overflow.ll
index 4440485af54bbaa..b3ffa209bc7004e 100644
--- a/llvm/test/CodeGen/X86/or-with-overflow.ll
+++ b/llvm/test/CodeGen/X86/or-with-overflow.ll
@@ -161,19 +161,13 @@ define i32 @or_i32_rr(i32 %0, i32 %1) {
define i64 @or_i64_ri(i64 %0, i64 %1) nounwind {
; X86-LABEL: or_i64_ri:
; X86: # %bb.0:
-; X86-NEXT: pushl %esi
; X86-NEXT: movl {{[0-9]+}}(%esp), %eax
; X86-NEXT: movl {{[0-9]+}}(%esp), %edx
-; X86-NEXT: movl %eax, %ecx
-; X86-NEXT: orl $17, %ecx
-; X86-NEXT: cmpl $1, %ecx
-; X86-NEXT: movl %edx, %esi
-; X86-NEXT: sbbl $0, %esi
-; X86-NEXT: jl .LBB6_2
+; X86-NEXT: testl %edx, %edx
+; X86-NEXT: js .LBB6_2
; X86-NEXT: # %bb.1:
-; X86-NEXT: movl %ecx, %eax
+; X86-NEXT: orl $17, %eax
; X86-NEXT: .LBB6_2:
-; X86-NEXT: popl %esi
; X86-NEXT: retl
;
; X64-LABEL: or_i64_ri:
|
RKSimon
changed the title
|
@RKSimon Do you have more issues/projects I can work on? |
|
Will this be merged soon? |
|
This change seemed to have broken this build bot yesterday. https://gitlab.e4s.io/uo-public/llvm-sollve/-/pipelines/9388/ |
|
@ajarmusch Please can you provide any more information? I can't even find a reference to 9103b1d on the log |
|
@RKSimon: I received this link by the mail yesterday: |
That was fixed by 632022e |
|
632022e looks ok: https://alive2.llvm.org/ce/z/V33G3f Please can you confirm why -lFortranRuntime is missing? FAILED: bin/external-hello-world
: && /usr/local/llvm/16.0.6/bin/clang++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wno-deprecated-copy -Wno-string-conversion -Wno-ctad-maybe-unsupported -Wno-unused-command-line-argument -Wstring-conversion -Wcovered-switch-default -Wno-nested-anon-types -O3 -DNDEBUG -Wl,-rpath-link,/home/gitlab-runner-sollve/builds/yP7whQwj9/0/uo-public/llvm-sollve/build/./lib -Wl,--gc-sections tools/flang/examples/ExternalHelloWorld/CMakeFiles/external-hello-world.dir/external-hello.cpp.o -o bin/external-hello-world -Wl,-rpath,"\$ORIGIN/../lib:" -lpthread -lFortranRuntime && :
/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12/../../../../bin/ld: cannot find -lFortranRuntime: No such file or directory |
|
thanks for checking - I'll ask the CI admin |
|
@ajarmusch Any update? |
|
It was a different commit that caused the failure. Trying to prevent another false blame |
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.