[LoopReroll] Make root-finding more aggressive.
Allow using an instruction other than a mul or phi as the base for
root-finding. For example, the included testcase includes a loop
which requires using a getelementptr as the base for root-finding.
Differential Revision: https://reviews.llvm.org/D26529
llvm-svn: 287588
diff --git a/llvm/test/Transforms/LoopReroll/basic.ll b/llvm/test/Transforms/LoopReroll/basic.ll
index 0c8f5d8..096b17b 100644
--- a/llvm/test/Transforms/LoopReroll/basic.ll
+++ b/llvm/test/Transforms/LoopReroll/basic.ll
@@ -575,6 +575,37 @@
ret void
}
+define void @gep-indexing(i32* nocapture %x) {
+entry:
+ %call = tail call i32 @foo(i32 0) #1
+ br label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+ %0 = mul nsw i64 %indvars.iv, 3
+ %arrayidx = getelementptr inbounds i32, i32* %x, i64 %0
+ store i32 %call, i32* %arrayidx, align 4
+ %arrayidx4 = getelementptr inbounds i32, i32* %arrayidx, i64 1
+ store i32 %call, i32* %arrayidx4, align 4
+ %arrayidx9 = getelementptr inbounds i32, i32* %arrayidx, i64 2
+ store i32 %call, i32* %arrayidx9, align 4
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ %exitcond = icmp eq i64 %indvars.iv.next, 500
+ br i1 %exitcond, label %for.end, label %for.body
+
+; CHECK-LABEL: @gep-indexing
+; CHECK: for.body:
+; CHECK-NEXT: %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+; CHECK-NEXT: %scevgep = getelementptr i32, i32* %x, i64 %indvars.iv
+; CHECK-NEXT: store i32 %call, i32* %scevgep, align 4
+; CHECK-NEXT: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+; CHECK-NEXT: %exitcond2 = icmp eq i32* %scevgep, %scevgep1
+; CHECK-NEXT: br i1 %exitcond2, label %for.end, label %for.body
+
+for.end: ; preds = %for.body
+ ret void
+}
+
define void @unordered_atomic_ops(i32* noalias %buf_0, i32* noalias %buf_1) {
; CHECK-LABEL: @unordered_atomic_ops(