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