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llvm-project/polly/test/ForwardOpTree/noforward_load_writebetween.ll

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[ForwardOpTree] Use known array content analysis to forward load instructions. This is an addition to the -polly-optree pass that reuses the array content analysis from DeLICM to find array elements that contain the same value as the value loaded when the target statement instance is executed. The analysis is now enabled by default. The known content analysis could also be used to rematerialize any llvm::Value that was written to some array element, but currently only loads are forwarded. Differential Revision: https://reviews.llvm.org/D36380 llvm-svn: 310279
2017-08-08 02:40:29 +08:00
; RUN: opt %loadPolly -polly-optree -analyze < %s | FileCheck %s -match-full-lines
;
; Cannot rematerialize %val from B[0] at bodyC because B[0] has been
; overwritten in bodyB.
;
[test] Add descriptions and pseudocode to tests. NFC. llvm-svn: 310385
2017-08-09 01:26:19 +08:00
; for (int j = 0; j < n; j += 1) {
; bodyA:
; double val = B[j];
;
; bodyB:
; B[j] = 0.0;
;
; bodyC:
; A[j] = val;
; }
;
[ForwardOpTree] Use known array content analysis to forward load instructions. This is an addition to the -polly-optree pass that reuses the array content analysis from DeLICM to find array elements that contain the same value as the value loaded when the target statement instance is executed. The analysis is now enabled by default. The known content analysis could also be used to rematerialize any llvm::Value that was written to some array element, but currently only loads are forwarded. Differential Revision: https://reviews.llvm.org/D36380 llvm-svn: 310279
2017-08-08 02:40:29 +08:00
define void @func(i32 %n, double* noalias nonnull %A, double* noalias nonnull %B) {
entry:
br label %for
for:
%j = phi i32 [0, %entry], [%j.inc, %inc]
%j.cmp = icmp slt i32 %j, %n
br i1 %j.cmp, label %bodyA, label %exit
bodyA:
%B_idx = getelementptr inbounds double, double* %B, i32 %j
%val = load double, double* %B_idx
br label %bodyB
bodyB:
store double 0.0, double* %B_idx
br label %bodyC
bodyC:
%A_idx = getelementptr inbounds double, double* %A, i32 %j
store double %val, double* %A_idx
br label %inc
inc:
%j.inc = add nuw nsw i32 %j, 1
br label %for
exit:
br label %return
return:
ret void
}
; CHECK: ForwardOpTree executed, but did not modify anything