1 files changed, 74 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/assume_inevitable.ll b/llvm/test/Transforms/InstCombine/assume_inevitable.ll
new file mode 100644
index 00000000000..a063775b057
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/assume_inevitable.ll
@@ -0,0 +1,74 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; Check that assume is propagated backwards through all
+; operations that are `isGuaranteedToTransferExecutionToSuccessor`
+; (it should reach the load and mark it as `align 32`).
+define i32 @assume_inevitable(i32* %a, i32* %b, i8* %c) {
+; CHECK-LABEL: @assume_inevitable(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[M:%.*]] = alloca i64, align 8
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 4
+; CHECK-NEXT:    [[LOADRES:%.*]] = load i32, i32* [[B:%.*]], align 4
+; CHECK-NEXT:    [[LOADRES2:%.*]] = call i32 @llvm.annotation.i32(i32 [[LOADRES]], i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str1, i64 0, i64 0), i32 2)
+; CHECK-NEXT:    store i32 [[LOADRES2]], i32* [[A]], align 4
+; CHECK-NEXT:    [[DUMMY_EQ:%.*]] = icmp ugt i32 [[LOADRES]], 42
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[DUMMY_EQ]])
+; CHECK-NEXT:    [[M_I8:%.*]] = bitcast i64* [[M]] to i8*
+; CHECK-NEXT:    [[M_A:%.*]] = call i8* @llvm.ptr.annotation.p0i8(i8* nonnull [[M_I8]], i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str1, i64 0, i64 0), i32 2)
+; CHECK-NEXT:    [[M_X:%.*]] = bitcast i8* [[M_A]] to i64*
+; CHECK-NEXT:    [[OBJSZ:%.*]] = call i64 @llvm.objectsize.i64.p0i8(i8* [[C:%.*]], i1 false, i1 false, i1 false)
+; CHECK-NEXT:    store i64 [[OBJSZ]], i64* [[M_X]], align 4
+; CHECK-NEXT:    [[PTRINT:%.*]] = ptrtoint i32* [[A]] to i64
+; CHECK-NEXT:    [[MASKEDPTR:%.*]] = and i64 [[PTRINT]], 31
+; CHECK-NEXT:    [[MASKCOND:%.*]] = icmp eq i64 [[MASKEDPTR]], 0
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[MASKCOND]])
+; CHECK-NEXT:    ret i32 [[TMP0]]
+;
+entry:
+  %dummy = alloca i8, align 4
+  %m = alloca i64
+  %0 = load i32, i32* %a, align 4
+
+  ; START perform a bunch of inevitable operations
+  %loadres = load i32, i32* %b
+  %loadres2 = call i32 @llvm.annotation.i32(i32 %loadres, i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str1, i32 0, i32 0), i32 2)
+  store i32 %loadres2, i32* %a
+
+  %dummy_eq = icmp ugt i32 %loadres, 42
+  tail call void @llvm.assume(i1 %dummy_eq)
+
+  call void @llvm.lifetime.start.p0i8(i64 1, i8* %dummy)
+  %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %dummy)
+  call void @llvm.invariant.end.p0i8({}* %i, i64 1, i8* %dummy)
+  call void @llvm.lifetime.end.p0i8(i64 1, i8* %dummy)
+
+  %m_i8 = bitcast i64* %m to i8*
+  %m_a = call i8* @llvm.ptr.annotation.p0i8(i8* %m_i8, i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str1, i32 0, i32 0), i32 2)
+  %m_x = bitcast i8* %m_a to i64*
+  %objsz = call i64 @llvm.objectsize.i64.p0i8(i8* %c, i1 false)
+  store i64 %objsz, i64* %m_x
+  ; END perform a bunch of inevitable operations
+
+  ; AND here's the assume:
+  %ptrint = ptrtoint i32* %a to i64
+  %maskedptr = and i64 %ptrint, 31
+  %maskcond = icmp eq i64 %maskedptr, 0
+  tail call void @llvm.assume(i1 %maskcond)
+
+  ret i32 %0
+}
+
+@.str = private unnamed_addr constant [4 x i8] c"sth\00", section "llvm.metadata"
+@.str1 = private unnamed_addr constant [4 x i8] c"t.c\00", section "llvm.metadata"
+
+declare i64 @llvm.objectsize.i64.p0i8(i8*, i1)
+declare i32 @llvm.annotation.i32(i32, i8*, i8*, i32)
+declare i8* @llvm.ptr.annotation.p0i8(i8*, i8*, i8*, i32)
+
+declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture)
+declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
+
+declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture)
+declare void @llvm.invariant.end.p0i8({}*, i64, i8* nocapture)
+declare void @llvm.assume(i1)