[LoopStrengthReduce] Don't bother rewriting PHIs in catchswitch blocks

The catchswitch instruction cannot be split, don't bother trying to
rewrite it.

This fixes PR31627.

llvm-svn: 291966

1 files changed, 58 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopStrengthReduce/pr31627.ll b/llvm/test/Transforms/LoopStrengthReduce/pr31627.ll
new file mode 100644
index 00000000000..4bd4fc273d7
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/pr31627.ll
@@ -0,0 +1,58 @@
+; RUN: opt -S -loop-reduce < %s | FileCheck %s
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24215"
+
+define void @fn3() personality i32 (...)* @__CxxFrameHandler3 {
+entry:
+  %call = invoke i32 @fn2()
+          to label %for.cond.preheader unwind label %catch.dispatch2
+
+for.cond.preheader:                               ; preds = %entry
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond.preheader, %for.cond
+  %b.0 = phi i32 [ %inc, %for.cond ], [ %call, %for.cond.preheader ]
+  %inc = add nsw i32 %b.0, 1
+  invoke void @fn1(i32 %inc)
+          to label %for.cond unwind label %catch.dispatch
+
+; CHECK:   %[[add:.*]] = add i32 %call, 1
+; CHECK:   br label %for.cond
+
+; CHECK: for.cond:                                         ; preds = %for.cond, %for.cond.preheader
+; CHECK:   %[[lsr_iv:.*]] = phi i32 [ %lsr.iv.next, %for.cond ], [ %[[add]], %for.cond.preheader ]
+; CHECK:   %[[lsr_iv_next:.*]] = add i32 %lsr.iv, 1
+; CHECK:   invoke void @fn1(i32 %[[lsr_iv]])
+
+
+catch.dispatch:                                   ; preds = %for.cond
+  %0 = catchswitch within none [label %catch] unwind label %catch.dispatch2
+
+catch:                                            ; preds = %catch.dispatch
+  %1 = catchpad within %0 [i8* null, i32 64, i8* null]
+  invoke void @_CxxThrowException(i8* null, i8* null) #2 [ "funclet"(token %1) ]
+          to label %unreachable unwind label %catch.dispatch2
+
+catch.dispatch2:                                  ; preds = %catch.dispatch, %catch, %entry
+  %a.0 = phi i32 [ undef, %entry ], [ %call, %catch ], [ %call, %catch.dispatch ]
+  %2 = catchswitch within none [label %catch3] unwind to caller
+
+catch3:                                           ; preds = %catch.dispatch2
+  %3 = catchpad within %2 [i8* null, i32 64, i8* null]
+  call void @fn1(i32 %a.0) [ "funclet"(token %3) ]
+  catchret from %3 to label %try.cont4
+
+try.cont4:                                        ; preds = %catch3
+  ret void
+
+unreachable:                                      ; preds = %catch
+  unreachable
+}
+
+declare i32 @fn2()
+
+declare i32 @__CxxFrameHandler3(...)
+
+declare void @fn1(i32)
+
+declare void @_CxxThrowException(i8*, i8*)