dag-combine-ldst.ll
1.4 KB
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; RUN: llc < %s -mtriple=arm-eabi -mattr=+v4t -O0 | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK_O0
; RUN: llc < %s -mtriple=arm-eabi -mattr=+v4t -O1 | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK_O1
; In /O0, the addition must not be eliminated. This happens when the load
; and store are folded by the DAGCombiner. In /O1 and above, the optimization
; must be executed.
; CHECK-LABEL: {{^}}main
; CHECK: mov [[TMP:r[0-9]+]], #0
; CHECK-NEXT: str [[TMP]], [sp, #4]
; CHECK_O0: str [[TMP]], [sp]
; CHECK_O0: ldr [[TMP:r[0-9]+]], [sp]
; CHECK_O0-NEXT: add [[TMP]], [[TMP]], #2
; CHECK_O1-NOT: ldr [[TMP:r[0-9]+]], [sp]
; CHECK_O1-NOT: add [[TMP]], [[TMP]], #2
define i32 @main() {
bb:
%tmp = alloca i32, align 4
%tmp1 = alloca i32, align 4
store i32 0, i32* %tmp, align 4
store i32 0, i32* %tmp1, align 4
%tmp2 = load i32, i32* %tmp1, align 4
%tmp3 = add nsw i32 %tmp2, 2
store i32 %tmp3, i32* %tmp1, align 4
%tmp4 = load i32, i32* %tmp1, align 4
%tmp5 = icmp eq i32 %tmp4, 2
br i1 %tmp5, label %bb6, label %bb7
bb6: ; preds = %bb
store i32 0, i32* %tmp, align 4
br label %bb8
bb7: ; preds = %bb
store i32 5, i32* %tmp, align 4
br label %bb8
bb8: ; preds = %bb7, %bb6
%tmp9 = load i32, i32* %tmp, align 4
ret i32 %tmp9
}