; RUN: opt < %s -basicaa -sink -S | FileCheck %s @A = external global i32 @B = external global i32 ; Sink should sink the load past the store (which doesn't overlap) into ; the block that uses it. ; CHECK-LABEL: @foo( ; CHECK: true: ; CHECK-NEXT: %l = load i32, i32* @A ; CHECK-NEXT: ret i32 %l define i32 @foo(i1 %z) { %l = load i32, i32* @A store i32 0, i32* @B br i1 %z, label %true, label %false true: ret i32 %l false: ret i32 0 } ; But don't sink load volatiles... ; CHECK-LABEL: @foo2( ; CHECK: load volatile ; CHECK-NEXT: store i32 define i32 @foo2(i1 %z) { %l = load volatile i32, i32* @A store i32 0, i32* @B br i1 %z, label %true, label %false true: ret i32 %l false: ret i32 0 } ; Sink to the nearest post-dominator ; CHECK-LABEL: @diamond( ; CHECK: X: ; CHECK-NEXT: phi ; CHECK-NEXT: mul nsw ; CHECK-NEXT: sub define i32 @diamond(i32 %a, i32 %b, i32 %c) { %1 = mul nsw i32 %c, %b %2 = icmp sgt i32 %a, 0 br i1 %2, label %B0, label %B1 B0: ; preds = %0 br label %X B1: ; preds = %0 br label %X X: ; preds = %5, %3 %.01 = phi i32 [ %c, %B0 ], [ %a, %B1 ] %R = sub i32 %1, %.01 ret i32 %R } ; We shouldn't sink constant sized allocas from the entry block, since CodeGen ; interprets allocas outside the entry block as dynamically sized stack objects. ; CHECK-LABEL: @alloca_nosink ; CHECK: entry: ; CHECK-NEXT: alloca define i32 @alloca_nosink(i32 %a, i32 %b) { entry: %0 = alloca i32 %1 = icmp ne i32 %a, 0 br i1 %1, label %if, label %endif if: %2 = getelementptr i32, i32* %0, i32 1 store i32 0, i32* %0 store i32 1, i32* %2 %3 = getelementptr i32, i32* %0, i32 %b %4 = load i32, i32* %3 ret i32 %4 endif: ret i32 0 } ; Make sure we sink dynamic sized allocas ; CHECK-LABEL: @alloca_sink_dynamic ; CHECK: entry: ; CHECK-NOT: alloca ; CHECK: if: ; CHECK-NEXT: alloca define i32 @alloca_sink_dynamic(i32 %a, i32 %b, i32 %size) { entry: %0 = alloca i32, i32 %size %1 = icmp ne i32 %a, 0 br i1 %1, label %if, label %endif if: %2 = getelementptr i32, i32* %0, i32 1 store i32 0, i32* %0 store i32 1, i32* %2 %3 = getelementptr i32, i32* %0, i32 %b %4 = load i32, i32* %3 ret i32 %4 endif: ret i32 0 } ; We also want to sink allocas that are not in the entry block. These ; will already be considered as dynamically sized stack objects, so sinking ; them does no further damage. ; CHECK-LABEL: @alloca_sink_nonentry ; CHECK: if0: ; CHECK-NOT: alloca ; CHECK: if: ; CHECK-NEXT: alloca define i32 @alloca_sink_nonentry(i32 %a, i32 %b, i32 %c) { entry: %cmp = icmp ne i32 %c, 0 br i1 %cmp, label %endif, label %if0 if0: %0 = alloca i32 %1 = icmp ne i32 %a, 0 br i1 %1, label %if, label %endif if: %2 = getelementptr i32, i32* %0, i32 1 store i32 0, i32* %0 store i32 1, i32* %2 %3 = getelementptr i32, i32* %0, i32 %b %4 = load i32, i32* %3 ret i32 %4 endif: ret i32 0 }