83 lines
2.3 KiB
LLVM
83 lines
2.3 KiB
LLVM
; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s
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; An example run where SCEV(%postinc)->getStart() may overflow:
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;
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; %start = INT_SMAX
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; %low.limit = INT_SMIN
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; %high.limit = < not used >
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;
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; >> entry:
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; %postinc.start = INT_SMIN
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;
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; >> loop:
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; %idx = %start
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; %postinc = INT_SMIN
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; %postinc.inc = INT_SMIN + 1
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; %postinc.sext = sext(INT_SMIN) = i64 INT32_SMIN
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; %break.early = INT_SMIN `slt` INT_SMIN = false
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; br i1 false, ___, %early.exit
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;
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; >> early.exit:
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; ret i64 INT32_SMIN
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define i64 @bad.0(i32 %start, i32 %low.limit, i32 %high.limit) {
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; CHECK-LABEL: Classifying expressions for: @bad.0
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entry:
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%postinc.start = add i32 %start, 1
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br label %loop
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loop:
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%idx = phi i32 [ %start, %entry ], [ %idx.inc, %continue ]
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%postinc = phi i32 [ %postinc.start, %entry ], [ %postinc.inc, %continue ]
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%postinc.inc = add nsw i32 %postinc, 1
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%postinc.sext = sext i32 %postinc to i64
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; CHECK: %postinc.sext = sext i32 %postinc to i64
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; CHECK-NEXT: --> {(sext i32 (1 + %start) to i64),+,1}<nsw><%loop>
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%break.early = icmp slt i32 %postinc, %low.limit
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br i1 %break.early, label %continue, label %early.exit
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continue:
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%idx.inc = add nsw i32 %idx, 1
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%cmp = icmp slt i32 %idx.inc, %high.limit
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br i1 %cmp, label %loop, label %exit
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exit:
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ret i64 0
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early.exit:
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ret i64 %postinc.sext
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}
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define i64 @bad.1(i32 %start, i32 %low.limit, i32 %high.limit, i1* %unknown) {
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; CHECK-LABEL: Classifying expressions for: @bad.1
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entry:
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%postinc.start = add i32 %start, 1
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br label %loop
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loop:
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%idx = phi i32 [ %start, %entry ], [ %idx.inc, %continue ], [ %idx.inc, %continue.1 ]
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%postinc = phi i32 [ %postinc.start, %entry ], [ %postinc.inc, %continue ], [ %postinc.inc, %continue.1 ]
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%postinc.inc = add nsw i32 %postinc, 1
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%postinc.sext = sext i32 %postinc to i64
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; CHECK: %postinc.sext = sext i32 %postinc to i64
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; CHECK-NEXT: --> {(sext i32 (1 + %start) to i64),+,1}<nsw><%loop>
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%break.early = icmp slt i32 %postinc, %low.limit
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br i1 %break.early, label %continue.1, label %early.exit
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continue.1:
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%cond = load volatile i1, i1* %unknown
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%idx.inc = add nsw i32 %idx, 1
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br i1 %cond, label %loop, label %continue
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continue:
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%cmp = icmp slt i32 %idx.inc, %high.limit
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br i1 %cmp, label %loop, label %exit
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exit:
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ret i64 0
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early.exit:
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ret i64 %postinc.sext
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}
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