Bail out if too many alias run-time-check comparisions would be needed

This fixes a crash observed in ffmpeg.

llvm-svn: 233480

1 files changed, 52 insertions, 0 deletions

diff --git a/polly/test/ScopInfo/aliasing_many_arrays_to_compare.ll b/polly/test/ScopInfo/aliasing_many_arrays_to_compare.ll
new file mode 100644
index 000000000000..cdc3a6437cef
--- /dev/null
+++ b/polly/test/ScopInfo/aliasing_many_arrays_to_compare.ll
@@ -0,0 +1,52 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s --check-prefix=FOUND
+; RUN: opt %loadPolly -polly-scops -analyze -polly-rtc-max-arrays-per-group=3 < %s | FileCheck %s --check-prefix=IGNORED
+;
+; FOUND: Function: foo
+; IGNORED-NOT: Function: foo
+;
+;    void foo(float *A, float *B, float *C, float *D) {
+;      for (long i = 0; i < 100; i++) {
+;        A[i]++;
+;        B[i]++;
+;        C[i]++;
+;        D[i]++;
+;      }
+;    }
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @foo(float* %A, float* %B, float* %C, float* %D) {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %i.0 = phi i64 [ 0, %entry ], [ %inc7, %for.inc ]
+  %exitcond = icmp ne i64 %i.0, 100
+  br i1 %exitcond, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %arrayidx = getelementptr inbounds float, float* %A, i64 %i.0
+  %tmp = load float, float* %arrayidx, align 4
+  %inc = fadd float %tmp, 1.000000e+00
+  store float %inc, float* %arrayidx, align 4
+  %arrayidx1 = getelementptr inbounds float, float* %B, i64 %i.0
+  %tmp1 = load float, float* %arrayidx1, align 4
+  %inc2 = fadd float %tmp1, 1.000000e+00
+  store float %inc2, float* %arrayidx1, align 4
+  %arrayidx3 = getelementptr inbounds float, float* %C, i64 %i.0
+  %tmp2 = load float, float* %arrayidx3, align 4
+  %inc4 = fadd float %tmp2, 1.000000e+00
+  store float %inc4, float* %arrayidx3, align 4
+  %arrayidx5 = getelementptr inbounds float, float* %D, i64 %i.0
+  %tmp3 = load float, float* %arrayidx5, align 4
+  %inc6 = fadd float %tmp3, 1.000000e+00
+  store float %inc6, float* %arrayidx5, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %inc7 = add nuw nsw i64 %i.0, 1
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret void
+}