Write coalescing combines write accesses that - Write the same llvm::Value. - Write to the same array. - Unless they do not write anything in a statement instance (partial writes), write to the same element. - There is no other access between them that accesses the same element. This is particularly useful after DeLICM, which leaves partial writes to disjoint domains. Differential Revision: https://reviews.llvm.org/D36010 llvm-svn: 309489
39 lines
800 B
LLVM
39 lines
800 B
LLVM
; RUN: opt %loadPolly -polly-import-jscop -polly-import-jscop-postfix=transformed -polly-simplify -analyze < %s | FileCheck -match-full-lines %s
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;
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; Do not combine stores if there is a write between them.
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;
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; for (int j = 0; j < n; j += 1) {
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; A[0] = 42.0;
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; A[0] = 21.0;
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; A[0] = 42.0;
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; }
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;
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define void @nocoalesce_writebetween(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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store double 42.0, double* %A
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store double 21.0, double* %A
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store double 42.0, 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: SCoP could not be simplified
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