[FIX] Prevent compile time problems due to complex invariant loads

  This cures the symptoms we see in h264 of SPEC2006 but not the cause.

llvm-svn: 262327

1 files changed, 70 insertions, 0 deletions

diff --git a/polly/test/Isl/CodeGen/invariant_load_complex_condition.ll b/polly/test/Isl/CodeGen/invariant_load_complex_condition.ll
new file mode 100644
index 00000000000..b371bf12e57
--- /dev/null
+++ b/polly/test/Isl/CodeGen/invariant_load_complex_condition.ll
@@ -0,0 +1,70 @@
+; RUN: opt %loadPolly -S -polly-codegen < %s | FileCheck %s
+;
+; Extracted from h246 in SPEC 2006.
+;
+; TODO: We check that we do compile this benchmark in reasonable time.
+;       To do so we currently bail out due to the complex access range
+;       (multiple modulos) of the invariant load.
+;
+; FIXME: We should not bail with a false RTC here.
+;
+; CHECK-LABEL: polly.preload.begin:
+; CHECK-NOT:     br i1
+; CHECK-NOT:     br label
+; CHECK:         br i1 false, label %polly.start, label %entry.split
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+%struct.IP = type { i32****, i32***, %struct.P, %struct.S, %struct.m }
+%struct.P = type { i32 }
+%struct.S = type { i32 }
+%struct.D = type { i32 }
+%struct.B = type { i32 }
+%struct.E = type { i32 }
+%struct.s = type { i32 }
+%struct.M = type { i32 }
+%struct.C = type { i32 }
+%struct.T = type { i32 }
+%struct.R = type { i32 }
+%struct.m = type { i32 }
+%struct.d = type { i32 }
+
+@img = external global %struct.IP*, align 8
+
+; Function Attrs: nounwind uwtable
+define void @dct_luma(i32 %block_x, i32 %block_y) #0 {
+entry:
+  br label %entry.split
+
+entry.split:                                      ; preds = %entry
+  %div = sdiv i32 %block_x, 4
+  %div1 = sdiv i32 %block_y, 4
+  %rem = srem i32 %div1, 2
+  %mul4 = shl nsw i32 %rem, 1
+  %rem5 = srem i32 %div, 2
+  %add6 = add nsw i32 %mul4, %rem5
+  %idxprom = sext i32 %add6 to i64
+  %0 = load %struct.IP*, %struct.IP** @img, align 8
+  %cofAC = getelementptr inbounds %struct.IP, %struct.IP* %0, i32 0, i32 0
+  %1 = load i32****, i32***** %cofAC, align 8
+  %arrayidx = getelementptr inbounds i32***, i32**** %1, i64 0
+  %2 = load i32***, i32**** %arrayidx, align 8
+  %arrayidx8 = getelementptr inbounds i32**, i32*** %2, i64 %idxprom
+  %3 = load i32**, i32*** %arrayidx8, align 8
+  %mb_data = getelementptr inbounds %struct.IP, %struct.IP* %0, i64 0, i32 4
+  %4 = load %struct.m, %struct.m* %mb_data, align 8
+  br i1 false, label %land.rhs, label %land.end
+
+land.rhs:                                         ; preds = %entry.split
+  br label %land.end
+
+land.end:                                         ; preds = %land.rhs, %entry.split
+  %5 = phi i1 [ false, %entry.split ], [ undef, %land.rhs ]
+  br i1 %5, label %for.cond104.preheader, label %for.cond34.preheader
+
+for.cond34.preheader:                             ; preds = %land.end
+  unreachable
+
+for.cond104.preheader:                            ; preds = %land.end
+  unreachable
+}