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| ; RUN: opt < %s -sccp -S | FileCheck %s
; This is a basic sanity check for constant propagation. The add instruction
; should be eliminated.
define i32 @test1(i1 %B) {
br i1 %B, label %BB1, label %BB2
BB1: ; preds = %0
%Val = add i32 0, 0 ; <i32> [#uses=1]
br label %BB3
BB2: ; preds = %0
br label %BB3
BB3: ; preds = %BB2, %BB1
%Ret = phi i32 [ %Val, %BB1 ], [ 1, %BB2 ] ; <i32> [#uses=1]
ret i32 %Ret
; CHECK-LABEL: @test1(
; CHECK: %Ret = phi i32 [ 0, %BB1 ], [ 1, %BB2 ]
}
; This is the test case taken from appel's book that illustrates a hard case
; that SCCP gets right.
;
define i32 @test2(i32 %i0, i32 %j0) {
; CHECK-LABEL: @test2(
BB1:
br label %BB2
BB2:
%j2 = phi i32 [ %j4, %BB7 ], [ 1, %BB1 ]
%k2 = phi i32 [ %k4, %BB7 ], [ 0, %BB1 ]
%kcond = icmp slt i32 %k2, 100
br i1 %kcond, label %BB3, label %BB4
BB3:
%jcond = icmp slt i32 %j2, 20
br i1 %jcond, label %BB5, label %BB6
; CHECK: BB3:
; CHECK-NEXT: br i1 true, label %BB5, label %BB6
BB4:
ret i32 %j2
; CHECK: BB4:
; CHECK-NEXT: ret i32 1
BB5:
%k3 = add i32 %k2, 1
br label %BB7
BB6:
%k5 = add i32 %k2, 1
br label %BB7
; CHECK: BB6:
; CHECK-NEXT: br label %BB7
BB7:
%j4 = phi i32 [ 1, %BB5 ], [ %k2, %BB6 ]
%k4 = phi i32 [ %k3, %BB5 ], [ %k5, %BB6 ]
br label %BB2
; CHECK: BB7:
; CHECK-NEXT: %k4 = phi i32 [ %k3, %BB5 ], [ undef, %BB6 ]
; CHECK-NEXT: br label %BB2
}
|