[ScalarEvolutionExpander] Properly insert no-op casts + EH Pads

We want to insert no-op casts as close as possible to the def.  This is
tricky when the cast is of a PHI node and the BasicBlocks between the
def and the use cannot hold any instructions.  Iteratively walk EH pads
until we hit a non-EH pad.

This fixes PR25326.

llvm-svn: 251393

1 files changed, 148 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopStrengthReduce/funclet.ll b/llvm/test/Transforms/LoopStrengthReduce/funclet.ll
new file mode 100644
index 00000000000..60bec76e7e6
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/funclet.ll
@@ -0,0 +1,148 @@
+; RUN: opt < %s -loop-reduce -S | FileCheck %s
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i686-pc-windows-msvc"
+
+declare i32 @_except_handler3(...)
+
+declare void @reserve()
+
+define void @f() personality i32 (...)* @_except_handler3 {
+entry:
+  br label %throw
+
+throw:                                            ; preds = %throw, %entry
+  %tmp96 = getelementptr inbounds i8, i8* undef, i32 1
+  invoke void @reserve()
+          to label %throw unwind label %pad
+
+pad:                                              ; preds = %throw
+  %phi2 = phi i8* [ %tmp96, %throw ]
+  terminatepad [] unwind label %blah
+
+blah:
+  catchpad [] to label %unreachable unwind label %blah3
+
+unreachable:
+  unreachable
+
+blah3:
+  catchendpad unwind label %blah2
+
+blah2:
+  %cleanuppadi4.i.i.i = cleanuppad []
+  br label %loop_body
+
+loop_body:                                        ; preds = %iter, %pad
+  %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah2 ]
+  %tmp100 = icmp eq i8* %tmp99, undef
+  br i1 %tmp100, label %unwind_out, label %iter
+
+iter:                                             ; preds = %loop_body
+  %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1
+  br i1 undef, label %unwind_out, label %loop_body
+
+unwind_out:                                       ; preds = %iter, %loop_body
+  cleanupret %cleanuppadi4.i.i.i unwind to caller
+}
+
+; CHECK-LABEL: define void @f(
+; CHECK: cleanuppad []
+; CHECK-NEXT: ptrtoint i8* %phi2 to i32
+
+define void @g() personality i32 (...)* @_except_handler3 {
+entry:
+  br label %throw
+
+throw:                                            ; preds = %throw, %entry
+  %tmp96 = getelementptr inbounds i8, i8* undef, i32 1
+  invoke void @reserve()
+          to label %throw unwind label %pad
+
+pad:
+  %phi2 = phi i8* [ %tmp96, %throw ]
+  catchpad [] to label %unreachable unwind label %blah
+
+unreachable:
+  unreachable
+
+blah:
+  %catchpad = catchpad [] to label %loop_body unwind label %blah3
+
+
+blah3:
+  catchendpad unwind to caller ;label %blah2
+
+unwind_out:
+  catchret %catchpad to label %leave
+
+leave:
+  ret void
+
+loop_body:                                        ; preds = %iter, %pad
+  %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah ]
+  %tmp100 = icmp eq i8* %tmp99, undef
+  br i1 %tmp100, label %unwind_out, label %iter
+
+iter:                                             ; preds = %loop_body
+  %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1
+  br i1 undef, label %unwind_out, label %loop_body
+}
+
+; CHECK-LABEL: define void @g(
+; CHECK: blah:
+; CHECK-NEXT: catchpad []
+; CHECK-NEXT: to label %loop_body.preheader
+
+; CHECK: loop_body.preheader:
+; CHECK-NEXT: ptrtoint i8* %phi2 to i32
+
+
+define void @h() personality i32 (...)* @_except_handler3 {
+entry:
+  br label %throw
+
+throw:                                            ; preds = %throw, %entry
+  %tmp96 = getelementptr inbounds i8, i8* undef, i32 1
+  invoke void @reserve()
+          to label %throw unwind label %pad
+
+pad:
+  catchpad [] to label %unreachable unwind label %blug
+
+unreachable:
+  unreachable
+
+blug:
+  %phi2 = phi i8* [ %tmp96, %pad ]
+  %catchpad = catchpad [] to label %blah2 unwind label %blah3
+
+blah2:
+  br label %loop_body
+
+blah3:
+  catchendpad unwind to caller ;label %blah2
+
+unwind_out:
+  catchret %catchpad to label %leave
+
+leave:
+  ret void
+
+loop_body:                                        ; preds = %iter, %pad
+  %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah2 ]
+  %tmp100 = icmp eq i8* %tmp99, undef
+  br i1 %tmp100, label %unwind_out, label %iter
+
+iter:                                             ; preds = %loop_body
+  %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1
+  br i1 undef, label %unwind_out, label %loop_body
+}
+
+; CHECK-LABEL: define void @h(
+; CHECK: blug:
+; CHECK: catchpad []
+; CHECK-NEXT: to label %blah2
+
+; CHECK: blah2:
+; CHECK-NEXT: ptrtoint i8* %phi2 to i32