37 lines
1.3 KiB
LLVM
37 lines
1.3 KiB
LLVM
; This is the test case taken from Appel's book that illustrates a hard case
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; that SCCP gets right, and when followed by ADCE, is completely eliminated
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;
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; RUN: opt < %s -sccp -simplifycfg -indvars -loop-deletion -dce -simplifycfg -S | not grep br
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define i32 @"test function"(i32 %i0, i32 %j0) {
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BB1:
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br label %BB2
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BB2: ; preds = %BB7, %BB1
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%j2 = phi i32 [ %j4, %BB7 ], [ 1, %BB1 ] ; <i32> [#uses=2]
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%k2 = phi i32 [ %k4, %BB7 ], [ 0, %BB1 ] ; <i32> [#uses=4]
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%kcond = icmp slt i32 %k2, 100 ; <i1> [#uses=1]
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br i1 %kcond, label %BB3, label %BB4
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BB3: ; preds = %BB2
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%jcond = icmp slt i32 %j2, 20 ; <i1> [#uses=1]
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br i1 %jcond, label %BB5, label %BB6
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BB4: ; preds = %BB2
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ret i32 %j2
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BB5: ; preds = %BB3
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%k3 = add i32 %k2, 1 ; <i32> [#uses=1]
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br label %BB7
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BB6: ; preds = %BB3
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%k5 = add i32 %k2, 1 ; <i32> [#uses=1]
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br label %BB7
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BB7: ; preds = %BB6, %BB5
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%j4 = phi i32 [ 1, %BB5 ], [ %k2, %BB6 ] ; <i32> [#uses=1]
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%k4 = phi i32 [ %k3, %BB5 ], [ %k5, %BB6 ] ; <i32> [#uses=1]
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br label %BB2
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}
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