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0446d81e2d
This new pass removes unnecessary accesses and writes. It currently supports 2 simplifications, but more are planned. It removes write accesses that write a loaded value back to the location it was loaded from. It is a typical artifact from DeLICM. Removing it will get rid of bogus dependencies later in dependency analysis. It also removes statements without side-effects. ScopInfo already removes these, but the removal of unnecessary writes can result in more side-effect free statements. Differential Revision: https://reviews.llvm.org/D30820 llvm-svn: 297473
42 lines
793 B
LLVM
42 lines
793 B
LLVM
; RUN: opt %loadPolly -polly-simplify -analyze < %s | FileCheck %s -match-full-lines
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;
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; Remove redundant store (a store that writes the same value already
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; at the destination)
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;
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; for (int j = 0; j < n; j += 1)
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; A[0] = A[0];
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;
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define void @func(i32 %n, double* noalias nonnull %A) {
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entry:
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br label %for
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for:
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%j = phi i32 [0, %entry], [%j.inc, %inc]
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%j.cmp = icmp slt i32 %j, %n
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br i1 %j.cmp, label %body, label %exit
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body:
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%val = load double, double* %A
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store double %val, double* %A
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br label %inc
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inc:
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%j.inc = add nuw nsw i32 %j, 1
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br label %for
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exit:
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br label %return
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return:
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ret void
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}
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; CHECK: Statistics {
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; CHECK: Redundant writes removed: 1
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; CHECK: Stmts removed: 1
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; CHECK: }
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; CHECK: After accesses {
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; CHECK-NEXT: }
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