| ; 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) |