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; 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
}
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