91b62d5c89
Summary: This patch adds Root Node to the DDG. The purpose of the root node is to create a single entry node that allows graph walk iterators to iterate through all nodes of the graph, making sure that no node is left unvisited during a graph walk (eg. SCC or DFS). Once the DDG is fully constructed it will have exactly one root node. Every node in the graph is reachable from the root. The algorithm for connecting the root node is based on depth-first-search that keeps track of visited nodes to try to avoid creating unnecessary edges. Authored By: bmahjour Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert Reviewed By: Meinersbur Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto, ppc-slack Tag: #llvm Differential Revision: https://reviews.llvm.org/D67970 llvm-svn: 373386
53 lines
1.9 KiB
LLVM
53 lines
1.9 KiB
LLVM
; RUN: opt < %s -disable-output "-passes=print<ddg>" 2>&1 | FileCheck %s
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; CHECK-LABEL: 'DDG' for loop 'test1.for.body':
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; CHECK: Node Address:[[N1:0x[0-9a-f]*]]:single-instruction
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; CHECK-NEXT: Instructions:
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; CHECK-NEXT: %i2.03 = phi i64 [ 0, %for.body.lr.ph ], [ %inc2, %test1.for.body ]
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; CHECK: Node Address:[[N2:0x[0-9a-f]*]]:single-instruction
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; CHECK-NEXT: Instructions:
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; CHECK-NEXT: %i1.02 = phi i64 [ 0, %for.body.lr.ph ], [ %inc, %test1.for.body ]
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; CHECK: Node Address:[[ROOT:0x[0-9a-f]*]]:root
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; CHECK-NEXT: Edges:
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; CHECK-NEXT: [rooted] to [[N1]]
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; CHECK-NEXT: [rooted] to [[N2]]
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;; // Two separate components in the graph. Root node must link to both.
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;; void test1(unsigned long n, float * restrict a, float * restrict b) {
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;; for (unsigned long i1 = 0, i2 = 0; i1 < n; i1++, i2++) {
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;; a[i1] = 1;
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;; b[i2] = -1;
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;; }
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;; }
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define void @test1(i64 %n, float* noalias %a, float* noalias %b) {
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entry:
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%cmp1 = icmp ult i64 0, %n
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br i1 %cmp1, label %for.body.lr.ph, label %for.end
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for.body.lr.ph: ; preds = %entry
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br label %test1.for.body
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test1.for.body: ; preds = %for.body.lr.ph, %test1.for.body
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%i2.03 = phi i64 [ 0, %for.body.lr.ph ], [ %inc2, %test1.for.body ]
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%i1.02 = phi i64 [ 0, %for.body.lr.ph ], [ %inc, %test1.for.body ]
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%arrayidx = getelementptr inbounds float, float* %a, i64 %i1.02
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store float 1.000000e+00, float* %arrayidx, align 4
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%arrayidx1 = getelementptr inbounds float, float* %b, i64 %i2.03
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store float -1.000000e+00, float* %arrayidx1, align 4
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%inc = add i64 %i1.02, 1
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%inc2 = add i64 %i2.03, 1
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%cmp = icmp ult i64 %inc, %n
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br i1 %cmp, label %test1.for.body, label %for.cond.for.end_crit_edge
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for.cond.for.end_crit_edge: ; preds = %test1.for.body
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br label %for.end
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for.end: ; preds = %for.cond.for.end_crit_edge, %entry
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ret void
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}
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