1 files changed, 138 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LICM/invariant.start.ll b/llvm/test/Transforms/LICM/invariant.start.ll
new file mode 100644
index 00000000000..d5d44757c40
--- /dev/null
+++ b/llvm/test/Transforms/LICM/invariant.start.ll
@@ -0,0 +1,138 @@
+; RUN: opt -licm -basicaa -licm-n2-threshold=0 < %s -S | FileCheck %s
+; RUN: opt -licm -basicaa -licm-n2-threshold=200 < %s -S | FileCheck %s --check-prefix=ALIAS-N2
+; RUN: opt -aa-pipeline=basic-aa -licm-n2-threshold=0 -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop(licm)' < %s -S | FileCheck %s
+; RUN: opt -aa-pipeline=basic-aa -licm-n2-threshold=200 -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop(licm)' < %s -S | FileCheck %s --check-prefix=ALIAS-N2
+
+define void @test1(i1 %cond, i32* %ptr) {
+; CHECK-LABEL: @test1(
+; CHECK-LABEL: entry:
+; CHECK: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; CHECK: %val = load i32, i32* %ptr
+; CHECK-LABEL: loop:
+
+; ALIAS-N2-LABEL: @test1(
+; ALIAS-N2-LABEL: entry:
+; ALIAS-N2: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; ALIAS-N2: %val = load i32, i32* %ptr
+; ALIAS-N2-LABEL: loop:
+
+entry:
+  br label %loop
+
+loop:
+  %x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
+  call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+  %val = load i32, i32* %ptr
+  %x.inc = add i32 %x, %val
+  br label %loop
+}
+
+;; despite the loop varying invariant.start, we should be
+;; able to hoist the load
+define void @test2(i1 %cond, i32* %ptr) {
+; CHECK-LABEL: @test2(
+; CHECK-LABEL: entry:
+; CHECK: %val = load i32, i32* %ptr
+; CHECK-LABEL: loop:
+; CHECK: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %piv)
+
+; ALIAS-N2-LABEL: @test2(
+; ALIAS-N2-LABEL: entry:
+; ALIAS-N2:         %val = load i32, i32* %ptr
+; ALIAS-N2-LABEL: loop:
+; ALIAS-N2:         call {}* @llvm.invariant.start.p0i32(i64 4, i32* %piv)
+entry:
+  br label %loop
+
+loop:
+  %x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
+  %piv = getelementptr i32, i32* %ptr, i32 %x
+  call {}* @llvm.invariant.start.p0i32(i64 4, i32* %piv)
+  %val = load i32, i32* %ptr
+  %x.inc = add i32 %x, %val
+  br label %loop
+}
+
+define void @test3(i1 %cond, i32* %ptr) {
+; CHECK-LABEL: @test3(
+; CHECK-LABEL: entry:
+; CHECK: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; CHECK: %val = load i32, i32* %ptr
+; CHECK-LABEL: loop:
+
+; ALIAS-N2-LABEL: @test3(
+; ALIAS-N2-LABEL: entry:
+; ALIAS-N2: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; ALIAS-N2: %val = load i32, i32* %ptr
+; ALIAS-N2-LABEL: loop:
+entry:
+  br label %loop
+
+loop:
+  %x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
+  call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+  %val = load i32, i32* %ptr
+  %p2 = getelementptr i32, i32* %ptr, i32 1
+  store volatile i32 0, i32* %p2
+  %x.inc = add i32 %x, %val
+  br label %loop
+}
+
+; can't hoist due to init in loop, only well defined if loop exits
+; on first iteration, but we don't bother checking for that currently
+define void @test4(i1 %cond, i32* %ptr) {
+; CHECK-LABEL: @test4(
+; CHECK-LABEL: entry:
+; CHECK-LABEL: loop:
+; CHECK:   store i32 0, i32* %ptr
+; CHECK: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; CHECK: %val = load i32, i32* %ptr
+
+; ALIAS-N2-LABEL: @test4(
+; ALIAS-N2-LABEL: entry:
+; ALIAS-N2-LABEL: loop:
+; ALIAS-N2:   store i32 0, i32* %ptr
+; ALIAS-N2: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; ALIAS-N2: %val = load i32, i32* %ptr
+entry:
+  br label %loop
+
+loop:
+  %x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
+  store i32 0, i32* %ptr
+  call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+  %val = load i32, i32* %ptr
+  %x.inc = add i32 %x, %val
+  br label %loop
+}
+
+; don't try to reason about scopes
+define void @test5(i1 %cond, i32* %ptr) {
+; CHECK-LABEL: @test5(
+; CHECK-LABEL: entry:
+; CHECK-LABEL: loop:
+; CHECK:   store i32 0, i32* %ptr
+; CHECK: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; CHECK: %val = load i32, i32* %ptr
+
+; ALIAS-N2-LABEL: @test5(
+; ALIAS-N2-LABEL: entry:
+; ALIAS-N2-LABEL: loop:
+; ALIAS-N2:   store i32 0, i32* %ptr
+; ALIAS-N2: call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+; ALIAS-N2: %val = load i32, i32* %ptr
+entry:
+  br label %loop
+
+loop:
+  %x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
+  store i32 0, i32* %ptr
+  %scope = call {}* @llvm.invariant.start.p0i32(i64 4, i32* %ptr)
+  %val = load i32, i32* %ptr
+  call void @llvm.invariant.end.p0i32({}* %scope, i64 4, i32* %ptr)
+  %x.inc = add i32 %x, %val
+  br label %loop
+}
+
+declare {}* @llvm.invariant.start.p0i32(i64, i32*)
+declare void @llvm.invariant.end.p0i32({}*, i64, i32*)