a6b2de3b59
This pass 'forwards' operand trees into statements that use them in order to avoid scalar dependencies. This minimal implementation handles only the case of speculatable instructions. We will successively add support for: - Hoisted loads - Read-only values - Synthesizable values - Loads - PHIs - Forwarding only parts of the tree Differential Revision: https://reviews.llvm.org/D35754 llvm-svn: 308825
63 lines
1.6 KiB
LLVM
63 lines
1.6 KiB
LLVM
; RUN: opt %loadPolly -polly-optree -analyze < %s | FileCheck %s -match-full-lines
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;
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; Move %val to %bodyB, so %bodyA can be removed (by -polly-simplify)
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;
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; for (int j = 0; j < n; j += 1) {
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; bodyA:
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; double val = 21.0 + 21.0;
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;
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; bodyB:
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; A[0] = val;
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; }
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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 %bodyA, label %exit
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bodyA:
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%val = fadd double 21.0, 21.0
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br label %bodyB
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bodyB:
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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: Instructions copied: 1
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; CHECK: Operand trees forwarded: 1
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; CHECK: Statements with forwarded operand trees: 1
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; CHECK: }
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; CHECK: After statements {
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; CHECK-NEXT: Stmt_bodyA
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; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
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; CHECK-NEXT: [n] -> { Stmt_bodyA[i0] -> MemRef_val[] };
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; CHECK-NEXT: Instructions {
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; CHECK-NEXT: %val = fadd double 2.100000e+01, 2.100000e+01
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; CHECK-NEXT: }
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; CHECK-NEXT: Stmt_bodyB
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; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
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; CHECK-NEXT: [n] -> { Stmt_bodyB[i0] -> MemRef_A[0] };
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; CHECK-NEXT: Instructions {
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; CHECK-NEXT: %val = fadd double 2.100000e+01, 2.100000e+01
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; CHECK-NEXT: store double %val, double* %A
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; CHECK-NEXT: }
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; CHECK-NEXT: }
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