Add Rpass-missed and Rpass-analysis reports to the loop vectorizer. The remarks give the vector width of vectorized loops and a brief analysis of loops that fail to be vectorized. For example, an analysis will be generated for loops containing control flow that cannot be simplified to a select. The optimization remarks also give the debug location of expressions that cannot be vectorized, for example the location of an unvectorizable call.

Reviewed by: Arnold Schwaighofer git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211721 91177308-0d34-0410-b5e6-96231b3b80d8
2025-11-01 15:17:25 +00:00 · 2014-06-25 17:50:15 +00:00
parent cae1ea691d
commit d5a8fa72bb
5 changed files with 511 additions and 27 deletions
--- a/test/Transforms/LoopVectorize/control-flow.ll
+++ b/test/Transforms/LoopVectorize/control-flow.ll
@@ -0,0 +1,78 @@
+; RUN: opt < %s -loop-vectorize -force-vector-width=4 -S -pass-remarks-missed='loop-vectorize' -pass-remarks-analysis='loop-vectorize' 2>&1 | FileCheck %s
+
+; C/C++ code for control flow test
+; int test(int *A, int Length) {
+;   for (int i = 0; i < Length; i++) {
+;     if (A[i] > 10.0) goto end;
+;     A[i] = 0;
+;   }
+; end:
+;   return 0;
+; }
+
+; CHECK: remark: source.cpp:5:9: loop not vectorized: loop control flow is not understood by vectorizer
+; CHECK: remark: source.cpp:5:9: loop not vectorized: vectorization was not specified
+
+; CHECK: _Z4testPii
+; CHECK-NOT: x i32>
+; CHECK: ret
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+; Function Attrs: nounwind optsize ssp uwtable
+define i32 @_Z4testPii(i32* nocapture %A, i32 %Length) #0 {
+entry:
+  %cmp8 = icmp sgt i32 %Length, 0, !dbg !10
+  br i1 %cmp8, label %for.body.preheader, label %end, !dbg !10
+
+for.body.preheader:                               ; preds = %entry
+  br label %for.body, !dbg !12
+
+for.body:                                         ; preds = %for.body.preheader, %if.else
+  %indvars.iv = phi i64 [ %indvars.iv.next, %if.else ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv, !dbg !12
+  %0 = load i32* %arrayidx, align 4, !dbg !12, !tbaa !15
+  %cmp1 = icmp sgt i32 %0, 10, !dbg !12
+  br i1 %cmp1, label %end.loopexit, label %if.else, !dbg !12
+
+if.else:                                          ; preds = %for.body
+  store i32 0, i32* %arrayidx, align 4, !dbg !19, !tbaa !15
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !10
+  %1 = trunc i64 %indvars.iv.next to i32, !dbg !10
+  %cmp = icmp slt i32 %1, %Length, !dbg !10
+  br i1 %cmp, label %for.body, label %end.loopexit, !dbg !10
+
+end.loopexit:                                     ; preds = %if.else, %for.body
+  br label %end
+
+end:                                              ; preds = %end.loopexit, %entry
+  ret i32 0, !dbg !20
+}
+
+attributes #0 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8}
+!llvm.ident = !{!9}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0", i1 true, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 2}
+!1 = metadata !{metadata !"source.cpp", metadata !"."}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"test", metadata !"test", metadata !"", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, i32 (i32*, i32)* @_Z4testPii, null, null, metadata !2, i32 2}
+!5 = metadata !{i32 786473, metadata !1}
+!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !2, i32 0, null, null, null}
+!7 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
+!8 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!9 = metadata !{metadata !"clang version 3.5.0"}
+!10 = metadata !{i32 3, i32 8, metadata !11, null}
+!11 = metadata !{i32 786443, metadata !1, metadata !4, i32 3, i32 3, i32 0, i32 0}
+!12 = metadata !{i32 5, i32 9, metadata !13, null}
+!13 = metadata !{i32 786443, metadata !1, metadata !14, i32 5, i32 9, i32 0, i32 2}
+!14 = metadata !{i32 786443, metadata !1, metadata !11, i32 4, i32 3, i32 0, i32 1}
+!15 = metadata !{metadata !16, metadata !16, i64 0}
+!16 = metadata !{metadata !"int", metadata !17, i64 0}
+!17 = metadata !{metadata !"omnipotent char", metadata !18, i64 0}
+!18 = metadata !{metadata !"Simple C/C++ TBAA"}
+!19 = metadata !{i32 8, i32 7, metadata !13, null}
+!20 = metadata !{i32 12, i32 3, metadata !4, null}