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

llvm-svn: 211721

4 files changed, 328 insertions, 3 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
new file mode 100644
index 00000000000..6cdd29bda23
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
@@ -0,0 +1,160 @@
+; RUN: opt < %s -loop-vectorize -S -pass-remarks-missed='loop-vectorize' -pass-remarks-analysis='loop-vectorize' 2>&1 | FileCheck %s
+
+; C/C++ code for tests
+; void test(int *A, int Length) {
+; #pragma clang loop vectorize(enable) interleave(enable)
+;   for (int i = 0; i < Length; i++) {
+;     A[i] = i;
+;     if (A[i] > Length)
+;       break;
+;   }
+; }
+
+; void test_disabled(int *A, int Length) {
+; #pragma clang loop vectorize(disable) interleave(disable)
+;   for (int i = 0; i < Length; i++)
+;     A[i] = i;
+; }
+
+; void test_array_bounds(int *A, int *B, int Length) {
+; #pragma clang loop vectorize(enable)
+;   for (int i = 0; i < Length; i++)
+;     A[i] = A[B[i]];
+; }
+
+; File, line, and column should match those specified in the metadata
+; CHECK: remark: source.cpp:4:5: loop not vectorized: could not determine number of loop iterations
+; CHECK: remark: source.cpp:4:5: loop not vectorized: vectorization was not specified
+; CHECK: remark: source.cpp:13:5: loop not vectorized: vector width and interleave count are explicitly set to 1
+; CHECK: remark: source.cpp:19:5: loop not vectorized: cannot identify array bounds
+; CHECK: remark: source.cpp:19:5: loop not vectorized: vectorization is explicitly enabled
+
+; CHECK: _Z4testPii
+; CHECK-NOT: x i32>
+; CHECK: ret
+
+; CHECK: _Z13test_disabledPii
+; CHECK-NOT: x i32>
+; CHECK: ret
+
+; CHECK: _Z17test_array_boundsPiS_i
+; 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 void @_Z4testPii(i32* nocapture %A, i32 %Length) #0 {
+entry:
+  %cmp10 = icmp sgt i32 %Length, 0, !dbg !12
+  br i1 %cmp10, label %for.body, label %for.end, !dbg !12, !llvm.loop !14
+
+for.body:                                         ; preds = %entry, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv, !dbg !16
+  %0 = trunc i64 %indvars.iv to i32, !dbg !16
+  store i32 %0, i32* %arrayidx, align 4, !dbg !16, !tbaa !18
+  %cmp3 = icmp sle i32 %0, %Length, !dbg !22
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !12
+  %1 = trunc i64 %indvars.iv.next to i32
+  %cmp = icmp slt i32 %1, %Length, !dbg !12
+  %or.cond = and i1 %cmp3, %cmp, !dbg !22
+  br i1 %or.cond, label %for.body, label %for.end, !dbg !22
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void, !dbg !24
+}
+
+; Function Attrs: nounwind optsize ssp uwtable
+define void @_Z13test_disabledPii(i32* nocapture %A, i32 %Length) #0 {
+entry:
+  %cmp4 = icmp sgt i32 %Length, 0, !dbg !25
+  br i1 %cmp4, label %for.body, label %for.end, !dbg !25, !llvm.loop !27
+
+for.body:                                         ; preds = %entry, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv, !dbg !30
+  %0 = trunc i64 %indvars.iv to i32, !dbg !30
+  store i32 %0, i32* %arrayidx, align 4, !dbg !30, !tbaa !18
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !25
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32, !dbg !25
+  %exitcond = icmp eq i32 %lftr.wideiv, %Length, !dbg !25
+  br i1 %exitcond, label %for.end, label %for.body, !dbg !25, !llvm.loop !27
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void, !dbg !31
+}
+
+; Function Attrs: nounwind optsize ssp uwtable
+define void @_Z17test_array_boundsPiS_i(i32* nocapture %A, i32* nocapture readonly %B, i32 %Length) #0 {
+entry:
+  %cmp9 = icmp sgt i32 %Length, 0, !dbg !32
+  br i1 %cmp9, label %for.body.preheader, label %for.end, !dbg !32, !llvm.loop !34
+
+for.body.preheader:                               ; preds = %entry
+  br label %for.body, !dbg !35
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32* %B, i64 %indvars.iv, !dbg !35
+  %0 = load i32* %arrayidx, align 4, !dbg !35, !tbaa !18
+  %idxprom1 = sext i32 %0 to i64, !dbg !35
+  %arrayidx2 = getelementptr inbounds i32* %A, i64 %idxprom1, !dbg !35
+  %1 = load i32* %arrayidx2, align 4, !dbg !35, !tbaa !18
+  %arrayidx4 = getelementptr inbounds i32* %A, i64 %indvars.iv, !dbg !35
+  store i32 %1, i32* %arrayidx4, align 4, !dbg !35, !tbaa !18
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !32
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32, !dbg !32
+  %exitcond = icmp eq i32 %lftr.wideiv, %Length, !dbg !32
+  br i1 %exitcond, label %for.end.loopexit, label %for.body, !dbg !32, !llvm.loop !34
+
+for.end.loopexit:                                 ; preds = %for.body
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.loopexit, %entry
+  ret void, !dbg !36
+}
+
+attributes #0 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !10}
+!llvm.ident = !{!11}
+
+!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, metadata !7, metadata !8}
+!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, void (i32*, i32)* @_Z4testPii, null, null, metadata !2, i32 1}
+!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 786478, metadata !1, metadata !5, metadata !"test_disabled", metadata !"test_disabled", metadata !"", i32 10, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (i32*, i32)* @_Z13test_disabledPii, null, null, metadata !2, i32 10}
+!8 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"test_array_bounds", metadata !"test_array_bounds", metadata !"", i32 16, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (i32*, i32*, i32)* @_Z17test_array_boundsPiS_i, null, null, metadata !2, i32 16}
+!9 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
+!10 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!11 = metadata !{metadata !"clang version 3.5.0"}
+!12 = metadata !{i32 3, i32 8, metadata !13, null}
+!13 = metadata !{i32 786443, metadata !1, metadata !4, i32 3, i32 3, i32 0, i32 0}
+!14 = metadata !{metadata !14, metadata !15, metadata !15}
+!15 = metadata !{metadata !"llvm.loop.vectorize.enable", i1 true}
+!16 = metadata !{i32 4, i32 5, metadata !17, null}
+!17 = metadata !{i32 786443, metadata !1, metadata !13, i32 3, i32 36, i32 0, i32 1}
+!18 = metadata !{metadata !19, metadata !19, i64 0}
+!19 = metadata !{metadata !"int", metadata !20, i64 0}
+!20 = metadata !{metadata !"omnipotent char", metadata !21, i64 0}
+!21 = metadata !{metadata !"Simple C/C++ TBAA"}
+!22 = metadata !{i32 5, i32 9, metadata !23, null}
+!23 = metadata !{i32 786443, metadata !1, metadata !17, i32 5, i32 9, i32 0, i32 2}
+!24 = metadata !{i32 8, i32 1, metadata !4, null}
+!25 = metadata !{i32 12, i32 8, metadata !26, null}
+!26 = metadata !{i32 786443, metadata !1, metadata !7, i32 12, i32 3, i32 0, i32 3}
+!27 = metadata !{metadata !27, metadata !28, metadata !29}
+!28 = metadata !{metadata !"llvm.loop.vectorize.unroll", i32 1}
+!29 = metadata !{metadata !"llvm.loop.vectorize.width", i32 1}
+!30 = metadata !{i32 13, i32 5, metadata !26, null}
+!31 = metadata !{i32 14, i32 1, metadata !7, null}
+!32 = metadata !{i32 18, i32 8, metadata !33, null}
+!33 = metadata !{i32 786443, metadata !1, metadata !8, i32 18, i32 3, i32 0, i32 4}
+!34 = metadata !{metadata !34, metadata !15}
+!35 = metadata !{i32 19, i32 5, metadata !33, null}
+!36 = metadata !{i32 20, i32 1, metadata !8, null}
diff --git a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
index f1641762fdc..f6834477ff5 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
@@ -1,5 +1,6 @@
 ; RUN: opt < %s -loop-vectorize -mtriple=x86_64-unknown-linux -S -pass-remarks='loop-vectorize' 2>&1 | FileCheck -check-prefix=VECTORIZED %s
-; RUN: opt < %s -loop-vectorize -force-vector-width=1 -force-vector-unroll=4 -mtriple=x86_64-unknown-linux -S -pass-remarks='.*vectorize.*' 2>&1 | FileCheck -check-prefix=UNROLLED %s
+; RUN: opt < %s -loop-vectorize -force-vector-width=1 -force-vector-unroll=4 -mtriple=x86_64-unknown-linux -S -pass-remarks='loop-vectorize' 2>&1 | FileCheck -check-prefix=UNROLLED %s
+; RUN: opt < %s -loop-vectorize -force-vector-width=1 -force-vector-unroll=1 -mtriple=x86_64-unknown-linux -S -pass-remarks-analysis='loop-vectorize' 2>&1 | FileCheck -check-prefix=NONE %s
 
 ; This code has all the !dbg annotations needed to track source line information,
 ; but is missing the llvm.dbg.cu annotation. This prevents code generation from
@@ -8,8 +9,9 @@
 ; DEBUG-OUTPUT-NOT: .loc
 ; DEBUG-OUTPUT-NOT: {{.*}}.debug_info
 
-; VECTORIZED: remark: {{.*}}.c:17:8: vectorized loop (vectorization factor: 4, unrolling interleave factor: 1)
-; UNROLLED: remark: {{.*}}.c:17:8: unrolled with interleaving factor 4 (vectorization not beneficial)
+; VECTORIZED: remark: vectorization-remarks.c:17:8: vectorized loop (vectorization factor: 4, unrolling interleave factor: 1)
+; UNROLLED: remark: vectorization-remarks.c:17:8: unrolled with interleaving factor 4 (vectorization not beneficial)
+; NONE: remark: vectorization-remarks.c:17:8: loop not vectorized: vector width and interleave count are explicitly set to 1
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
diff --git a/llvm/test/Transforms/LoopVectorize/control-flow.ll b/llvm/test/Transforms/LoopVectorize/control-flow.ll
new file mode 100644
index 00000000000..e4ba77fa3da
--- /dev/null
+++ b/llvm/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}
diff --git a/llvm/test/Transforms/LoopVectorize/no_switch.ll b/llvm/test/Transforms/LoopVectorize/no_switch.ll
new file mode 100644
index 00000000000..52b42850f44
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/no_switch.ll
@@ -0,0 +1,85 @@
+; RUN: opt < %s -loop-vectorize -force-vector-width=4 -S -pass-remarks-missed='loop-vectorize' -pass-remarks-analysis='loop-vectorize' 2>&1 | FileCheck %s
+
+; CHECK: remark: source.cpp:4:5: loop not vectorized: loop contains a switch statement
+; CHECK: remark: source.cpp:4:5: loop not vectorized: vectorization is explicitly enabled with width 4
+
+; CHECK: _Z11test_switchPii
+; 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 void @_Z11test_switchPii(i32* nocapture %A, i32 %Length) #0 {
+entry:
+  %cmp18 = icmp sgt i32 %Length, 0, !dbg !10
+  br i1 %cmp18, label %for.body.preheader, label %for.end, !dbg !10, !llvm.loop !12
+
+for.body.preheader:                               ; preds = %entry
+  br label %for.body, !dbg !14
+
+for.body:                                         ; preds = %for.body.preheader, %for.inc
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv, !dbg !14
+  %0 = load i32* %arrayidx, align 4, !dbg !14, !tbaa !16
+  switch i32 %0, label %for.inc [
+    i32 0, label %sw.bb
+    i32 1, label %sw.bb3
+  ], !dbg !14
+
+sw.bb:                                            ; preds = %for.body
+  %1 = trunc i64 %indvars.iv to i32, !dbg !20
+  %mul = shl nsw i32 %1, 1, !dbg !20
+  br label %for.inc, !dbg !22
+
+sw.bb3:                                           ; preds = %for.body
+  %2 = trunc i64 %indvars.iv to i32, !dbg !23
+  store i32 %2, i32* %arrayidx, align 4, !dbg !23, !tbaa !16
+  br label %for.inc, !dbg !23
+
+for.inc:                                          ; preds = %sw.bb3, %for.body, %sw.bb
+  %storemerge = phi i32 [ %mul, %sw.bb ], [ 0, %for.body ], [ 0, %sw.bb3 ]
+  store i32 %storemerge, i32* %arrayidx, align 4, !dbg !20, !tbaa !16
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !10
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32, !dbg !10
+  %exitcond = icmp eq i32 %lftr.wideiv, %Length, !dbg !10
+  br i1 %exitcond, label %for.end.loopexit, label %for.body, !dbg !10, !llvm.loop !12
+
+for.end.loopexit:                                 ; preds = %for.inc
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.loopexit, %entry
+  ret void, !dbg !24
+}
+
+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_switch", metadata !"test_switch", metadata !"", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (i32*, i32)* @_Z11test_switchPii, null, null, metadata !2, i32 1}
+!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 !{metadata !12, metadata !13, metadata !13}
+!13 = metadata !{metadata !"llvm.loop.vectorize.enable", i1 true}
+!14 = metadata !{i32 4, i32 5, metadata !15, null}
+!15 = metadata !{i32 786443, metadata !1, metadata !11, i32 3, i32 36, i32 0, i32 1}
+!16 = metadata !{metadata !17, metadata !17, i64 0}
+!17 = metadata !{metadata !"int", metadata !18, i64 0}
+!18 = metadata !{metadata !"omnipotent char", metadata !19, i64 0}
+!19 = metadata !{metadata !"Simple C/C++ TBAA"}
+!20 = metadata !{i32 6, i32 7, metadata !21, null}
+!21 = metadata !{i32 786443, metadata !1, metadata !15, i32 4, i32 18, i32 0, i32 2}
+!22 = metadata !{i32 7, i32 5, metadata !21, null}
+!23 = metadata !{i32 9, i32 7, metadata !21, null}
+!24 = metadata !{i32 14, i32 1, metadata !4, null}