Teach IndVarSimplify's FixUsesBeforeDefs to handle InvokeInsts by

assuming that the use of the value is in a block dominated by the
"normal" destination. LangRef.html and other documentation sources
don't explicitly guarantee this, but it seems to be assumed in
other places in LLVM at least.

This fixes an assertion failure on the included testcase, which
is derived from the Ada testsuite.

FixUsesBeforeDefs is a temporary measure which I'm looking to
replace with a more capable solution.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72266 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 62 insertions, 1 deletions

diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 26015cf..89742c5 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -662,7 +662,11 @@ void IndVarSimplify::FixUsesBeforeDefs(Loop *L, SCEVExpander &Rewriter) {
         if (Z != NumPredsLeft.end() && Z->second != 0 && --Z->second == 0) {
           SmallVector<Instruction *, 4> UseWorkList;
           UseWorkList.push_back(Inst);
-          BasicBlock::iterator InsertPt = next(I);
+          BasicBlock::iterator InsertPt = I;
+          if (InvokeInst *II = dyn_cast<InvokeInst>(InsertPt))
+            InsertPt = II->getNormalDest()->begin();
+          else
+            ++InsertPt;
           while (isa<PHINode>(InsertPt)) ++InsertPt;
           do {
             Instruction *Use = UseWorkList.pop_back_val();
diff --git a/test/Transforms/IndVarSimplify/interesting-invoke-use.ll b/test/Transforms/IndVarSimplify/interesting-invoke-use.ll
new file mode 100644
index 0000000..b90d1e0
--- /dev/null
+++ b/test/Transforms/IndVarSimplify/interesting-invoke-use.ll
@@ -0,0 +1,57 @@
+; RUN: llvm-as < %s | opt -indvars
+
+; An invoke has a result value which is used in an "Interesting"
+; expression inside the loop. IndVars should be able to rewrite
+; the expression in the correct place.
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
+target triple = "i386-pc-linux-gnu"
+  %struct.string___XUB = type { i32, i32 }
+  %struct.string___XUP = type { [0 x i8]*, %struct.string___XUB* }
+@.str7 = external constant [24 x i8]            ; <[24 x i8]*> [#uses=1]
+@C.17.316 = external constant %struct.string___XUB              ; <%struct.string___XUB*> [#uses=1]
+
+define void @_ada_c35503g() {
+entry:
+  br label %bb
+
+bb:             ; preds = %bb, %entry
+  br i1 false, label %bb65.loopexit, label %bb
+
+bb65.loopexit:          ; preds = %bb
+  br label %bb123
+
+bb123:          ; preds = %bb178, %bb65.loopexit
+  %i.0 = phi i32 [ %3, %bb178 ], [ 0, %bb65.loopexit ]          ; <i32> [#uses=3]
+  %0 = invoke i32 @report__ident_int(i32 1)
+      to label %invcont127 unwind label %lpad266                ; <i32> [#uses=1]
+
+invcont127:             ; preds = %bb123
+  %1 = sub i32 %i.0, %0         ; <i32> [#uses=1]
+  %2 = icmp eq i32 0, %1                ; <i1> [#uses=1]
+  br i1 %2, label %bb178, label %bb128
+
+bb128:          ; preds = %invcont127
+  invoke void @system__img_int__image_integer(%struct.string___XUP* noalias sret null, i32 %i.0)
+      to label %invcont129 unwind label %lpad266
+
+invcont129:             ; preds = %bb128
+  invoke void @system__string_ops__str_concat(%struct.string___XUP* noalias sret null, [0 x i8]* bitcast ([24 x i8]* @.str7 to [0 x i8]*), %struct.string___XUB* @C.17.316, [0 x i8]* null, %struct.string___XUB* null)
+      to label %invcont138 unwind label %lpad266
+
+invcont138:             ; preds = %invcont129
+  unreachable
+
+bb178:          ; preds = %invcont127
+  %3 = add i32 %i.0, 1          ; <i32> [#uses=1]
+  br label %bb123
+
+lpad266:                ; preds = %invcont129, %bb128, %bb123
+  unreachable
+}
+
+declare void @system__img_int__image_integer(%struct.string___XUP* noalias sret, i32)
+
+declare void @system__string_ops__str_concat(%struct.string___XUP* noalias sret, [0 x i8]*, %struct.string___XUB*, [0 x i8]*, %struct.string___XUB*)
+
+declare i32 @report__ident_int(i32)