[llvm] 077dc5c - [DSE] Add tests that require phi translation to be removed.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 10 08:37:19 PST 2021
Author: Florian Hahn
Date: 2021-03-10T16:32:55Z
New Revision: 077dc5c87bd3a427560f60acd97056b5e95c70f8
URL: https://github.com/llvm/llvm-project/commit/077dc5c87bd3a427560f60acd97056b5e95c70f8
DIFF: https://github.com/llvm/llvm-project/commit/077dc5c87bd3a427560f60acd97056b5e95c70f8.diff
LOG: [DSE] Add tests that require phi translation to be removed.
Added:
llvm/test/Transforms/DeadStoreElimination/phi-translation.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Transforms/DeadStoreElimination/phi-translation.ll b/llvm/test/Transforms/DeadStoreElimination/phi-translation.ll
new file mode 100644
index 000000000000..9f764bdb0d0b
--- /dev/null
+++ b/llvm/test/Transforms/DeadStoreElimination/phi-translation.ll
@@ -0,0 +1,275 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -dse -S %s | FileCheck %s
+
+; TODO: Both the stores in %then and %else can be eliminated by translating %p
+; through the phi.
+define void @memoryphi_translate_1(i1 %c) {
+; CHECK-LABEL: @memoryphi_translate_1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A_1:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[A_2:%.*]] = alloca i8, align 1
+; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK: then:
+; CHECK-NEXT: store i8 0, i8* [[A_1]], align 1
+; CHECK-NEXT: br label [[END:%.*]]
+; CHECK: else:
+; CHECK-NEXT: store i8 9, i8* [[A_2]], align 1
+; CHECK-NEXT: br label [[END]]
+; CHECK: end:
+; CHECK-NEXT: [[P:%.*]] = phi i8* [ [[A_1]], [[THEN]] ], [ [[A_2]], [[ELSE]] ]
+; CHECK-NEXT: store i8 10, i8* [[P]], align 1
+; CHECK-NEXT: ret void
+;
+entry:
+ %a.1 = alloca i8
+ %a.2 = alloca i8
+ br i1 %c, label %then, label %else
+
+then:
+ store i8 0, i8* %a.1
+ br label %end
+
+else:
+ store i8 9, i8* %a.2
+ br label %end
+
+end:
+ %p = phi i8* [ %a.1, %then ], [ %a.2, %else ]
+ store i8 10, i8* %p
+ ret void
+}
+
+; TODO: The store in %else can be eliminated by translating %p through the phi.
+; The store in %then cannot be eliminated, because %a.1 is read before the final
+; store.
+define i8 @memoryphi_translate_2(i1 %c) {
+; CHECK-LABEL: @memoryphi_translate_2(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A_1:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[A_2:%.*]] = alloca i8, align 1
+; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK: then:
+; CHECK-NEXT: store i8 0, i8* [[A_1]], align 1
+; CHECK-NEXT: br label [[END:%.*]]
+; CHECK: else:
+; CHECK-NEXT: store i8 9, i8* [[A_2]], align 1
+; CHECK-NEXT: br label [[END]]
+; CHECK: end:
+; CHECK-NEXT: [[P:%.*]] = phi i8* [ [[A_1]], [[THEN]] ], [ [[A_2]], [[ELSE]] ]
+; CHECK-NEXT: [[L:%.*]] = load i8, i8* [[A_1]], align 1
+; CHECK-NEXT: store i8 10, i8* [[P]], align 1
+; CHECK-NEXT: ret i8 [[L]]
+;
+entry:
+ %a.1 = alloca i8
+ %a.2 = alloca i8
+ br i1 %c, label %then, label %else
+
+then:
+ store i8 0, i8* %a.1
+ br label %end
+
+else:
+ store i8 9, i8* %a.2
+ br label %end
+
+end:
+ %p = phi i8* [ %a.1, %then ], [ %a.2, %else ]
+ %l = load i8, i8* %a.1
+ store i8 10, i8* %p
+ ret i8 %l
+}
+
+; TODO: The store in %then can be eliminated by translating %p through the phi.
+; The store in %else cannot be eliminated, because %a.2 is read before the final
+; store.
+define i8 @memoryphi_translate_3(i1 %c) {
+; CHECK-LABEL: @memoryphi_translate_3(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A_1:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[A_2:%.*]] = alloca i8, align 1
+; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK: then:
+; CHECK-NEXT: store i8 0, i8* [[A_1]], align 1
+; CHECK-NEXT: br label [[END:%.*]]
+; CHECK: else:
+; CHECK-NEXT: store i8 9, i8* [[A_2]], align 1
+; CHECK-NEXT: br label [[END]]
+; CHECK: end:
+; CHECK-NEXT: [[P:%.*]] = phi i8* [ [[A_1]], [[THEN]] ], [ [[A_2]], [[ELSE]] ]
+; CHECK-NEXT: [[L:%.*]] = load i8, i8* [[A_2]], align 1
+; CHECK-NEXT: store i8 10, i8* [[P]], align 1
+; CHECK-NEXT: ret i8 [[L]]
+;
+entry:
+ %a.1 = alloca i8
+ %a.2 = alloca i8
+ br i1 %c, label %then, label %else
+
+then:
+ store i8 0, i8* %a.1
+ br label %end
+
+else:
+ store i8 9, i8* %a.2
+ br label %end
+
+end:
+ %p = phi i8* [ %a.1, %then ], [ %a.2, %else ]
+ %l = load i8, i8* %a.2
+ store i8 10, i8* %p
+ ret i8 %l
+}
+
+; No stores can be eliminated, because there's a load from the phi.
+define i8 @memoryphi_translate_4(i1 %c) {
+; CHECK-LABEL: @memoryphi_translate_4(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A_1:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[A_2:%.*]] = alloca i8, align 1
+; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK: then:
+; CHECK-NEXT: store i8 0, i8* [[A_1]], align 1
+; CHECK-NEXT: br label [[END:%.*]]
+; CHECK: else:
+; CHECK-NEXT: store i8 9, i8* [[A_2]], align 1
+; CHECK-NEXT: br label [[END]]
+; CHECK: end:
+; CHECK-NEXT: [[P:%.*]] = phi i8* [ [[A_1]], [[THEN]] ], [ [[A_2]], [[ELSE]] ]
+; CHECK-NEXT: [[L:%.*]] = load i8, i8* [[P]], align 1
+; CHECK-NEXT: store i8 10, i8* [[P]], align 1
+; CHECK-NEXT: ret i8 [[L]]
+;
+entry:
+ %a.1 = alloca i8
+ %a.2 = alloca i8
+ br i1 %c, label %then, label %else
+
+then:
+ store i8 0, i8* %a.1
+ br label %end
+
+else:
+ store i8 9, i8* %a.2
+ br label %end
+
+end:
+ %p = phi i8* [ %a.1, %then ], [ %a.2, %else ]
+ %l = load i8, i8* %p
+ store i8 10, i8* %p
+ ret i8 %l
+}
+
+; TODO: The store in %entry can be removed by translating %p through the phi.
+define void @memoryphi_translate_5(i1 %cond) {
+; CHECK-LABEL: @memoryphi_translate_5(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[B:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[C:%.*]] = alloca i8, align 1
+; CHECK-NEXT: store i8 0, i8* [[A]], align 1
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]]
+; CHECK: cond.true:
+; CHECK-NEXT: store i8 0, i8* [[C]], align 1
+; CHECK-NEXT: br label [[COND_END]]
+; CHECK: cond.end:
+; CHECK-NEXT: [[P:%.*]] = phi i8* [ [[B]], [[COND_TRUE]] ], [ [[A]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: store i8 0, i8* [[P]], align 1
+; CHECK-NEXT: call void @use(i8* [[P]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %a = alloca i8
+ %b = alloca i8
+ %c = alloca i8
+ store i8 0, i8* %a
+ br i1 %cond, label %cond.true, label %cond.end
+
+cond.true:
+ store i8 0, i8* %c
+ br label %cond.end
+
+cond.end:
+ %p = phi i8* [ %b, %cond.true ], [ %a, %entry ]
+ store i8 0, i8* %p
+ call void @use(i8* %p)
+ ret void
+}
+
+; TODO: The store in %entry can be removed by translating %p through the phi.
+; Same as @memoryphi_translate_5, but without stores in %cond.true, so there
+; is no MemoryPhi.
+define void @translate_without_memoryphi_1(i1 %cond) {
+; CHECK-LABEL: @translate_without_memoryphi_1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A:%.*]] = alloca i8, align 1
+; CHECK-NEXT: [[B:%.*]] = alloca i8, align 1
+; CHECK-NEXT: store i8 0, i8* [[A]], align 1
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]]
+; CHECK: cond.true:
+; CHECK-NEXT: br label [[COND_END]]
+; CHECK: cond.end:
+; CHECK-NEXT: [[P:%.*]] = phi i8* [ [[B]], [[COND_TRUE]] ], [ [[A]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: store i8 0, i8* [[P]], align 1
+; CHECK-NEXT: call void @use(i8* [[P]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %a = alloca i8
+ %b = alloca i8
+ store i8 0, i8* %a
+ br i1 %cond, label %cond.true, label %cond.end
+
+cond.true:
+ br label %cond.end
+
+cond.end:
+ %p = phi i8* [ %b, %cond.true ], [ %a, %entry ]
+ store i8 0, i8* %p
+ call void @use(i8* %p)
+ ret void
+}
+
+; In the test, translating through the phi results in a null address. Make sure
+; this does not cause a crash.
+define void @test_trans_null(i1 %c, i16* %ptr) {
+; CHECK-LABEL: @test_trans_null(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK: then:
+; CHECK-NEXT: br label [[EXIT:%.*]]
+; CHECK: else:
+; CHECK-NEXT: call void @fn()
+; CHECK-NEXT: [[BC:%.*]] = bitcast i8* undef to i16*
+; CHECK-NEXT: [[GEP_1:%.*]] = getelementptr inbounds i16, i16* [[BC]], i64 2
+; CHECK-NEXT: store i16 8, i16* [[GEP_1]], align 2
+; CHECK-NEXT: br label [[EXIT]]
+; CHECK: exit:
+; CHECK-NEXT: [[P:%.*]] = phi i16* [ [[PTR:%.*]], [[THEN]] ], [ [[BC]], [[ELSE]] ]
+; CHECK-NEXT: [[GEP_2:%.*]] = getelementptr inbounds i16, i16* [[P]], i64 2
+; CHECK-NEXT: store i16 8, i16* [[GEP_2]], align 2
+; CHECK-NEXT: ret void
+;
+entry:
+ br i1 %c, label %then, label %else
+
+then:
+ br label %exit
+
+else:
+ call void @fn()
+ %bc = bitcast i8* undef to i16*
+ %gep.1 = getelementptr inbounds i16, i16* %bc, i64 2
+ store i16 8, i16* %gep.1, align 2
+ br label %exit
+
+exit:
+ %p = phi i16* [ %ptr, %then ], [ %bc, %else ]
+ %gep.2 = getelementptr inbounds i16, i16* %p, i64 2
+ store i16 8, i16* %gep.2, align 2
+ ret void
+}
+
+
+declare void @use(i8*)
+declare void @fn()
More information about the llvm-commits
mailing list