; RUN: opt -S -licm < %s | FileCheck %s ; Note: the !invariant.load is there just solely to let us call @use() ; to add a fake use, and still have the aliasing work out. The call ; to @use(0) is just to provide a may-unwind exit out of the loop, so ; that LICM cannot hoist out the load simply because it is guaranteed ; to execute. declare void @use(i32) define void @f_0(i8* align 4 dereferenceable(1024) %ptr) { ; CHECK-LABEL: @f_0( ; CHECK: entry: ; CHECK: %val = load i32, i32* %ptr.i32 ; CHECK: br label %loop ; CHECK: loop: ; CHECK: call void @use(i32 0) ; CHECK-NEXT: call void @use(i32 %val) entry: %ptr.gep = getelementptr i8, i8* %ptr, i32 32 %ptr.i32 = bitcast i8* %ptr.gep to i32* br label %loop loop: call void @use(i32 0) %val = load i32, i32* %ptr.i32, !invariant.load !{} call void @use(i32 %val) br label %loop } define void @f_1(i8* align 4 dereferenceable_or_null(1024) %ptr) { ; CHECK-LABEL: @f_1( entry: %ptr.gep = getelementptr i8, i8* %ptr, i32 32 %ptr.i32 = bitcast i8* %ptr.gep to i32* %ptr_is_null = icmp eq i8* %ptr, null br i1 %ptr_is_null, label %leave, label %loop ; CHECK: loop.preheader: ; CHECK: %val = load i32, i32* %ptr.i32 ; CHECK: br label %loop ; CHECK: loop: ; CHECK: call void @use(i32 0) ; CHECK-NEXT: call void @use(i32 %val) loop: call void @use(i32 0) %val = load i32, i32* %ptr.i32, !invariant.load !{} call void @use(i32 %val) br label %loop leave: ret void } define void @f_2(i8* align 4 dereferenceable_or_null(1024) %ptr) { ; CHECK-LABEL: @f_2( ; CHECK-NOT: load ; CHECK: call void @use(i32 0) ; CHECK-NEXT: %val = load i32, i32* %ptr.i32, align 4, !invariant.load !0 ; CHECK-NEXT: call void @use(i32 %val) entry: ;; Can't hoist, since the alignment does not work out -- (<4 byte ;; aligned> + 30) is not necessarily 4 byte aligned. %ptr.gep = getelementptr i8, i8* %ptr, i32 30 %ptr.i32 = bitcast i8* %ptr.gep to i32* %ptr_is_null = icmp eq i8* %ptr, null br i1 %ptr_is_null, label %leave, label %loop loop: call void @use(i32 0) %val = load i32, i32* %ptr.i32, !invariant.load !{} call void @use(i32 %val) br label %loop leave: ret void } define void @checkLaunder(i8* align 4 dereferenceable(1024) %p) { ; CHECK-LABEL: @checkLaunder( ; CHECK: entry: ; CHECK: %l = call i8* @llvm.launder.invariant.group.p0i8(i8* %p) ; CHECK: %val = load i8, i8* %l ; CHECK: br label %loop ; CHECK: loop: ; CHECK: call void @use(i32 0) ; CHECK-NEXT: call void @use8(i8 %val) entry: %l = call i8* @llvm.launder.invariant.group.p0i8(i8* %p) br label %loop loop: call void @use(i32 0) %val = load i8, i8* %l, !invariant.load !{} call void @use8(i8 %val) br label %loop } declare i8* @llvm.launder.invariant.group.p0i8(i8*) declare void @use8(i8)