[llvm] r345456 - [Local] Keep K's range if K does not move when combining metadata.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Sat Oct 27 09:53:46 PDT 2018
Author: fhahn
Date: Sat Oct 27 09:53:45 2018
New Revision: 345456
URL: http://llvm.org/viewvc/llvm-project?rev=345456&view=rev
Log:
[Local] Keep K's range if K does not move when combining metadata.
As K has to dominate I, IIUC I's range metadata must be a subset of
K's. After Eli's recent clarification to the LangRef, loading a value
outside of the range is undefined behavior.
Therefore if I's range contains elements outside of K's range and we would load
one such value, K would cause undefined behavior.
In cases like hoisting/sinking, we still want the most generic range
over all code paths to/from the hoist/sink point. As suggested in the
patches related to D47339, I will refactor the handling of those
scenarios and try to decouple it from this function as follow up, once
we switched to a similar handling of metadata in most of
combineMetadata.
I updated some tests checking mostly the merging of metadata to keep the
metadata of to dominating load. The most interesting one is probably test8 in
test/Transforms/JumpThreading/thread-loads.ll. It contained a comment
about the alias metadata preventing us to eliminate the branch, but it
seem like the actual problem currently is that we merge the ranges of
both loads and cannot eliminate the icmp afterwards. With this patch, we
manage to eliminate the icmp, as the range of the first load excludes 8.
Reviewers: efriedma, nlopes, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D51629
Modified:
llvm/trunk/lib/Transforms/Utils/Local.cpp
llvm/trunk/test/Transforms/GVN/range.ll
llvm/trunk/test/Transforms/InstCombine/load-combine-metadata.ll
llvm/trunk/test/Transforms/JumpThreading/thread-loads.ll
llvm/trunk/test/Transforms/NewGVN/range.ll
Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=345456&r1=345455&r2=345456&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Sat Oct 27 09:53:45 2018
@@ -2315,7 +2315,15 @@ void llvm::combineMetadata(Instruction *
K->setMetadata(Kind, MDNode::intersect(JMD, KMD));
break;
case LLVMContext::MD_range:
- K->setMetadata(Kind, MDNode::getMostGenericRange(JMD, KMD));
+
+ // If K does move, use most generic range. Otherwise keep the range of
+ // K.
+ if (DoesKMove)
+ // FIXME: If K does move, we should drop the range info and nonnull.
+ // Currently this function is used with DoesKMove in passes
+ // doing hoisting/sinking and the current behavior of using the
+ // most generic range is correct in those cases.
+ K->setMetadata(Kind, MDNode::getMostGenericRange(JMD, KMD));
break;
case LLVMContext::MD_fpmath:
K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD));
Modified: llvm/trunk/test/Transforms/GVN/range.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/range.ll?rev=345456&r1=345455&r2=345456&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/range.ll (original)
+++ llvm/trunk/test/Transforms/GVN/range.ll Sat Oct 27 09:53:45 2018
@@ -2,7 +2,7 @@
define i32 @test1(i32* %p) {
; CHECK-LABEL: @test1(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range !0
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p, !range !0
@@ -12,8 +12,7 @@ define i32 @test1(i32* %p) {
define i32 @test2(i32* %p) {
; CHECK-LABEL: @test2(i32* %p)
-; CHECK: %a = load i32, i32* %p
-; CHECK-NOT: range
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p
@@ -23,7 +22,7 @@ define i32 @test2(i32* %p) {
define i32 @test3(i32* %p) {
; CHECK-LABEL: @test3(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[DISJOINT_RANGE:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p, !range !1
@@ -33,7 +32,7 @@ define i32 @test3(i32* %p) {
define i32 @test4(i32* %p) {
; CHECK-LABEL: @test4(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_RANGE:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p, !range !2
@@ -43,7 +42,7 @@ define i32 @test4(i32* %p) {
define i32 @test5(i32* %p) {
; CHECK-LABEL: @test5(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_SIGNED_RANGE:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE3:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !3
%b = load i32, i32* %p, !range !4
@@ -53,7 +52,7 @@ define i32 @test5(i32* %p) {
define i32 @test6(i32* %p) {
; CHECK-LABEL: @test6(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_TEST6:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE5:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !5
%b = load i32, i32* %p, !range !6
@@ -63,7 +62,7 @@ define i32 @test6(i32* %p) {
define i32 @test7(i32* %p) {
; CHECK-LABEL: @test7(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_TEST7:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE7:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !7
%b = load i32, i32* %p, !range !8
@@ -73,7 +72,7 @@ define i32 @test7(i32* %p) {
define i32 @test8(i32* %p) {
; CHECK-LABEL: @test8(i32* %p)
-; CHECK: %a = load i32, i32* %p
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE9:[0-9]+]]
; CHECK-NOT: range
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !9
@@ -82,11 +81,11 @@ define i32 @test8(i32* %p) {
ret i32 %c
}
-; CHECK: ![[DISJOINT_RANGE]] = !{i32 0, i32 2, i32 3, i32 5}
-; CHECK: ![[MERGED_RANGE]] = !{i32 0, i32 5}
-; CHECK: ![[MERGED_SIGNED_RANGE]] = !{i32 -5, i32 -2, i32 1, i32 5}
-; CHECK: ![[MERGED_TEST6]] = !{i32 10, i32 1}
-; CHECK: ![[MERGED_TEST7]] = !{i32 3, i32 4, i32 5, i32 2}
+; CHECK: ![[RANGE0]] = !{i32 0, i32 2}
+; CHECK: ![[RANGE3]] = !{i32 -5, i32 -2}
+; CHECK: ![[RANGE5]] = !{i32 10, i32 1}
+; CHECK: ![[RANGE7]] = !{i32 1, i32 2, i32 3, i32 4}
+; CHECK: ![[RANGE9]] = !{i32 1, i32 5}
!0 = !{i32 0, i32 2}
!1 = !{i32 3, i32 5}
Modified: llvm/trunk/test/Transforms/InstCombine/load-combine-metadata.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/load-combine-metadata.ll?rev=345456&r1=345455&r2=345456&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/load-combine-metadata.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/load-combine-metadata.ll Sat Oct 27 09:53:45 2018
@@ -17,7 +17,7 @@ define void @test_load_load_combine_meta
ret void
}
-; CHECK: ![[RANGE]] = !{i32 0, i32 5, i32 7, i32 9}
+; CHECK: ![[RANGE]] = !{i32 0, i32 5}
!0 = !{ i32 0, i32 5 }
!1 = !{ i32 7, i32 9 }
!2 = !{!2}
Modified: llvm/trunk/test/Transforms/JumpThreading/thread-loads.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/JumpThreading/thread-loads.ll?rev=345456&r1=345455&r2=345456&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/JumpThreading/thread-loads.ll (original)
+++ llvm/trunk/test/Transforms/JumpThreading/thread-loads.ll Sat Oct 27 09:53:45 2018
@@ -246,13 +246,15 @@ bb3:
ret i32 %res.0
}
-; Make sure we merge the aliasing metadata. (If we don't, we have a load
-; with the wrong metadata, so the branch gets incorrectly eliminated.)
+; Make sure we merge the aliasing metadata. We keep the range metadata for the
+; first load, as it dominates the second load. Hence we can eliminate the
+; branch.
define void @test8(i32*, i32*, i32*) {
; CHECK-LABEL: @test8(
-; CHECK: %a = load i32, i32* %0, !range !4
+; CHECK: %a = load i32, i32* %0, !range ![[RANGE4:[0-9]+]]
; CHECK-NEXT: store i32 %a
-; CHECK: br i1 %c
+; CHECK-NEXT: %xxx = tail call i32 (...) @f1()
+; CHECK-NEXT: ret void
%a = load i32, i32* %0, !tbaa !0, !range !4, !alias.scope !9, !noalias !10
%b = load i32, i32* %0, !range !5
store i32 %a, i32* %1
@@ -525,6 +527,8 @@ right_x:
ret i32 10
}
+; CHECK: ![[RANGE4]] = !{i32 0, i32 1}
+
!0 = !{!3, !3, i64 0}
!1 = !{!"omnipotent char", !2}
!2 = !{!"Simple C/C++ TBAA"}
Modified: llvm/trunk/test/Transforms/NewGVN/range.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/NewGVN/range.ll?rev=345456&r1=345455&r2=345456&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/NewGVN/range.ll (original)
+++ llvm/trunk/test/Transforms/NewGVN/range.ll Sat Oct 27 09:53:45 2018
@@ -2,7 +2,7 @@
define i32 @test1(i32* %p) {
; CHECK-LABEL: @test1(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range !0
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p, !range !0
@@ -12,8 +12,7 @@ define i32 @test1(i32* %p) {
define i32 @test2(i32* %p) {
; CHECK-LABEL: @test2(i32* %p)
-; CHECK: %a = load i32, i32* %p
-; CHECK-NOT: range
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p
@@ -23,7 +22,7 @@ define i32 @test2(i32* %p) {
define i32 @test3(i32* %p) {
; CHECK-LABEL: @test3(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[DISJOINT_RANGE:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p, !range !1
@@ -33,7 +32,7 @@ define i32 @test3(i32* %p) {
define i32 @test4(i32* %p) {
; CHECK-LABEL: @test4(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_RANGE:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE0]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !0
%b = load i32, i32* %p, !range !2
@@ -43,7 +42,7 @@ define i32 @test4(i32* %p) {
define i32 @test5(i32* %p) {
; CHECK-LABEL: @test5(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_SIGNED_RANGE:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE3:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !3
%b = load i32, i32* %p, !range !4
@@ -53,7 +52,7 @@ define i32 @test5(i32* %p) {
define i32 @test6(i32* %p) {
; CHECK-LABEL: @test6(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_TEST6:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE5:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !5
%b = load i32, i32* %p, !range !6
@@ -63,7 +62,7 @@ define i32 @test6(i32* %p) {
define i32 @test7(i32* %p) {
; CHECK-LABEL: @test7(i32* %p)
-; CHECK: %a = load i32, i32* %p, !range ![[MERGED_TEST7:[0-9]+]]
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE7:[0-9]+]]
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !7
%b = load i32, i32* %p, !range !8
@@ -73,7 +72,7 @@ define i32 @test7(i32* %p) {
define i32 @test8(i32* %p) {
; CHECK-LABEL: @test8(i32* %p)
-; CHECK: %a = load i32, i32* %p
+; CHECK: %a = load i32, i32* %p, !range ![[RANGE9:[0-9]+]]
; CHECK-NOT: range
; CHECK: %c = add i32 %a, %a
%a = load i32, i32* %p, !range !9
@@ -82,11 +81,11 @@ define i32 @test8(i32* %p) {
ret i32 %c
}
-; CHECK: ![[DISJOINT_RANGE]] = !{i32 0, i32 2, i32 3, i32 5}
-; CHECK: ![[MERGED_RANGE]] = !{i32 0, i32 5}
-; CHECK: ![[MERGED_SIGNED_RANGE]] = !{i32 -5, i32 -2, i32 1, i32 5}
-; CHECK: ![[MERGED_TEST6]] = !{i32 10, i32 1}
-; CHECK: ![[MERGED_TEST7]] = !{i32 3, i32 4, i32 5, i32 2}
+; CHECK: ![[RANGE0]] = !{i32 0, i32 2}
+; CHECK: ![[RANGE3]] = !{i32 -5, i32 -2}
+; CHECK: ![[RANGE5]] = !{i32 10, i32 1}
+; CHECK: ![[RANGE7]] = !{i32 1, i32 2, i32 3, i32 4}
+; CHECK: ![[RANGE9]] = !{i32 1, i32 5}
!0 = !{i32 0, i32 2}
!1 = !{i32 3, i32 5}
More information about the llvm-commits
mailing list