[SCEVAffinator] Fix handling of pwaff complexity limit.

nullptr is not a valid affine expression, and none of the callers check
for null, so we eventually hit an isl error and crash.

Instead, invalidate the scop and return a constant zero.

Differential Revision: https://reviews.llvm.org/D46445

llvm-svn: 332309

1 files changed, 37 insertions, 0 deletions

diff --git a/polly/test/ScopInfo/pwaff-complexity-bailout.ll b/polly/test/ScopInfo/pwaff-complexity-bailout.ll
new file mode 100644
index 00000000000..bf4934f8457
--- /dev/null
+++ b/polly/test/ScopInfo/pwaff-complexity-bailout.ll
@@ -0,0 +1,37 @@
+; RUN: opt %loadPolly -analyze -polly-scops -pass-remarks-analysis=.* < %s 2>&1 > /dev/null | FileCheck %s
+
+; Make sure we hit the complexity bailout, and don't crash.
+; CHECK: Low complexity assumption:       {  : false }
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "thumbv8--linux-android"
+
+define hidden void @f(i32 %arg1, i32 %arg2, i32 %cond, i32 %tmp, i32 %tmp196) {
+entry:
+  %div = sdiv i32 %tmp, 8
+  %div10 = sdiv i32 %arg1, 8
+  %div11 = sdiv i32 %tmp196, 2
+  %add = add nsw i32 %div10, %div11
+  %sub19 = add nsw i32 %div, -1
+  %cmp20 = icmp slt i32 %add, %sub19
+  %add.sub19 = select i1 %cmp20, i32 %add, i32 %sub19
+  %div469 = sdiv i32 %arg2, 8
+  %cmp.i68 = icmp slt i32 %div469, %cond
+  %cond.i = select i1 %cmp.i68, i32 %cond, i32 %div469
+  %sub.i69 = add i32 0, %div469
+  %cmp9.i = icmp sgt i32 %sub.i69, %add.sub19
+  %sub15.max_x.i = select i1 %cmp9.i, i32 %add.sub19, i32 %sub.i69
+  %sub30.i = sub nsw i32 %sub15.max_x.i, %cond.i
+  %add31.i = add nsw i32 %sub30.i, 1
+  br label %for.body.us.i
+
+for.body.us.i:
+  br label %for.body47.us.i
+
+for.body47.us.i:
+  %cmp45.us.i = icmp ult i32 0, %add31.i
+  br i1 %cmp45.us.i, label %for.body47.us.i, label %for.cond44.for.cond.cleanup46_crit_edge.us.i
+
+for.cond44.for.cond.cleanup46_crit_edge.us.i:
+  br label %for.body.us.i
+}