[LV] Stop saying "use -Rpass-analysis=loop-vectorize"

[anemet]

Summary

This is PR28376.

Unfortunately given the current structure of optimization diagnostics we
lack the capability to tell whether the user has
passed -Rpass-analysis=loop-vectorize since this is local to the
front-end (BackendConsumer::OptimizationRemarkHandler).

So rather than printing this even if the user has already
passed -Rpass-analysis, this patch just punts and stops recommending
this option. I don't think that getting this right is worth the
complexity.

[mzolotukhin]

Makes sense to me (you might want to wait for others' opinion though).

Michael

[hfinkel]

In D26563#593316, @mzolotukhin wrote:

Makes sense to me (you might want to wait for others' opinion though).

Michael

Yes, please. We should not mention Clang flags in backend messages.

lib/Transforms/Vectorize/LoopVectorize.cpp

void emitRemarkWithHints() const {
     if (Force.Value == LoopVectorizeHints::FK_Disabled)
       ORE.emit(OptimizationRemarkMissed(LV_NAME, "MissedExplicitlyDisabled",
                                         TheLoop->getStartLoc(),
                                         TheLoop->getHeader())
                << "loop not vectorized: vectorization is explicitly disabled");
     else {
       OptimizationRemarkMissed R(LV_NAME, "MissedDetails",
                                  TheLoop->getStartLoc(), TheLoop->getHeader());
-      R << "loop not vectorized: use -Rpass-analysis=loop-vectorize for more "
-           "info";
+      R << "loop not vectorized";
       if (Force.Value == LoopVectorizeHints::FK_Enabled) {
         R << " (Force=" << NV("Force", true);
         if (Width.Value != 0)
           R << ", Vector Width=" << NV("VectorWidth", Width.Value);
         if (Interleave.Value != 0)
           R << ", Interleave Count=" << NV("InterleaveCount", Interleave.Value);
         R << ")";
       }

test/Transforms/LoopVectorize/X86/no_fpmath.ll

 ; RUN: opt < %s -loop-vectorize -mtriple=x86_64-unknown-linux -S -pass-remarks='loop-vectorize' -pass-remarks-missed='loop-vectorize' -pass-remarks-analysis='loop-vectorize' 2>&1 | FileCheck %s
 
 ; CHECK: remark: no_fpmath.c:6:11: loop not vectorized: cannot prove it is safe to reorder floating-point operations
-; CHECK: remark: no_fpmath.c:6:14: loop not vectorized:
+; CHECK: remark: no_fpmath.c:6:14: loop not vectorized
 ; CHECK: remark: no_fpmath.c:17:14: vectorized loop (vectorization width: 2, interleaved count: 2)
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.10.0"
 
 ; Function Attrs: nounwind readonly ssp uwtable
 define double @cond_sum(i32* nocapture readonly %v, i32 %n) #0 !dbg !4 {
 entry:

test/Transforms/LoopVectorize/X86/no_fpmath_with_hotness.ll

 ; RUN: opt < %s -loop-vectorize -mtriple=x86_64-unknown-linux -S -pass-remarks=loop-vectorize -pass-remarks-missed=loop-vectorize -pass-remarks-analysis=loop-vectorize -pass-remarks-with-hotness 2>&1 | FileCheck %s
 ; RUN: opt < %s -passes=loop-vectorize -mtriple=x86_64-unknown-linux -S -pass-remarks=loop-vectorize -pass-remarks-missed=loop-vectorize -pass-remarks-analysis=loop-vectorize -pass-remarks-with-hotness 2>&1 | FileCheck %s
 
 ; CHECK: remark: no_fpmath.c:6:11: loop not vectorized: cannot prove it is safe to reorder floating-point operations (hotness: 300)
-; CHECK: remark: no_fpmath.c:6:14: loop not vectorized:
+; CHECK: remark: no_fpmath.c:6:14: loop not vectorized
 ; CHECK: remark: no_fpmath.c:17:14: vectorized loop (vectorization width: 2, interleaved count: 2) (hotness: 300)
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.10.0"
 
 ; Function Attrs: nounwind readonly ssp uwtable
 define double @cond_sum(i32* nocapture readonly %v, i32 %n) #0 !dbg !4 !prof !29 {
 entry:

test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll

 ; 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: use -Rpass-analysis=loop-vectorize for more info
+; CHECK: remark: source.cpp:4:5: loop not vectorized
 ; CHECK: remark: source.cpp:13:5: loop not vectorized: vectorization and interleaving are explicitly disabled, or vectorize width and interleave count are both 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: use -Rpass-analysis=loop-vectorize for more info
+; CHECK: remark: source.cpp:19:5: loop not vectorized
 ; CHECK: warning: source.cpp:19:5: loop not vectorized: failed explicitly specified loop vectorization
 
 ; CHECK: _Z4testPii
 ; CHECK-NOT: x i32>
 ; CHECK: ret
 
 ; CHECK: _Z13test_disabledPii
 ; CHECK-NOT: x i32>

test/Transforms/LoopVectorize/control-flow.ll

 ; RUN: opt < %s -loop-vectorize -force-vector-width=4 -S -pass-remarks-missed='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: use -Rpass-analysis=loop-vectorize for more info
+; CHECK: remark: source.cpp:5:9: loop not vectorized
 
 ; 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

test/Transforms/LoopVectorize/diag-with-hotness-info.ll

 ;  14
 ;  15 void unknown(char *A, char *B, char *C, char *D, char *E, int N) {
 ;  16   for(int i = 0; i < N; i++) {
 ;  17     A[i + 1] = A[i] + B[i];
 ;  18     C[i] = D[i] * E[i];
 ;  19   }
 ;  20 }
 
-; HOTNESS: remark: /tmp/s.c:2:3: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info (hotness: 300)
-; NO_HOTNESS: remark: /tmp/s.c:2:3: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info{{$}}
-; HOTNESS: remark: /tmp/s.c:9:3: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info (hotness: 5000)
-; NO_HOTNESS: remark: /tmp/s.c:9:3: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info{{$}}
-; BOTH: remark: /tmp/s.c:16:3: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info{{$}}
+; HOTNESS: remark: /tmp/s.c:2:3: loop not vectorized (hotness: 300)
+; NO_HOTNESS: remark: /tmp/s.c:2:3: loop not vectorized{{$}}
+; HOTNESS: remark: /tmp/s.c:9:3: loop not vectorized (hotness: 5000)
+; NO_HOTNESS: remark: /tmp/s.c:9:3: loop not vectorized{{$}}
+; BOTH: remark: /tmp/s.c:16:3: loop not vectorized{{$}}
 
 ; ModuleID = '/tmp/s.c'
 source_filename = "/tmp/s.c"
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 
 ; Function Attrs: norecurse nounwind ssp uwtable
 define void @cold(i8* nocapture %A, i8* nocapture readonly %B, i8* nocapture %C, i8* nocapture readonly %D, i8* nocapture readonly %E, i32 %N) local_unnamed_addr #0 !dbg !7 !prof !56 {
 entry:

test/Transforms/LoopVectorize/no_switch.ll

 ; RUN: opt < %s -loop-vectorize -force-vector-width=4 -S 2>&1 | FileCheck %s
 ; RUN: opt < %s -loop-vectorize -force-vector-width=1 -S 2>&1 | FileCheck %s -check-prefix=NOANALYSIS
 ; RUN: opt < %s -loop-vectorize -force-vector-width=4 -pass-remarks-missed='loop-vectorize' -S 2>&1 | FileCheck %s -check-prefix=MOREINFO
 
 ; CHECK: remark: source.cpp:4:5: loop not vectorized: loop contains a switch statement
 ; CHECK: warning: source.cpp:4:5: loop not vectorized: failed explicitly specified loop vectorization
 
 ; NOANALYSIS-NOT: remark: {{.*}}
 ; NOANALYSIS: warning: source.cpp:4:5: loop not interleaved: failed explicitly specified loop interleaving
 
 ; MOREINFO: remark: source.cpp:4:5: loop not vectorized: loop contains a switch statement
-; MOREINFO: remark: source.cpp:4:5: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info (Force=true, Vector Width=4)
+; MOREINFO: remark: source.cpp:4:5: loop not vectorized (Force=true, Vector Width=4)
 ; MOREINFO: warning: source.cpp:4:5: loop not vectorized: failed explicitly specified loop vectorization
 
 ; CHECK: _Z11test_switchPii
 ; CHECK-NOT: x i32>
 ; CHECK: ret
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"