[LoopVectorize] Pointer indicies may be wider than the pointer

If we are dealing with a pointer induction variable, isInductionPHI
gives back a step value of Stride / size of pointer.  However, we might
be indexing with a legal type wider than the pointer width.
Handle this by inserting casts where appropriate instead of crashing.

This fixes PR23954.

llvm-svn: 240877

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/ptr-indvar-crash.ll b/llvm/test/Transforms/LoopVectorize/X86/ptr-indvar-crash.ll
new file mode 100644
index 00000000000..56ea2f4c31d
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/X86/ptr-indvar-crash.ll
@@ -0,0 +1,20 @@
+; RUN: opt -slp-vectorizer -S %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @f(i128 %p1) {
+entry:
+  br label %while.body
+
+while.body:
+  %p.05 = phi i8* [ %add.ptr, %while.body ], [ null, %entry ]
+  %p1.addr.04 = phi i128 [ %sub, %while.body ], [ %p1, %entry ]
+  %add.ptr = getelementptr inbounds i8, i8* %p.05, i32 2
+  %sub = add nsw i128 %p1.addr.04, -2
+  %tobool = icmp eq i128 %sub, 0
+  br i1 %tobool, label %while.end, label %while.body
+
+while.end:
+  ret void
+}