Add delinearization testcase for ivs that do not follow the loop order

This is a test case that is currently failing, but that should start working
with an upcoming version of our delinearization pass.

llvm-svn: 207678

polly/test/ScopInfo/multidim_only_ivs_3d_reverse.ll

@@ -0,0 +1,71 @@
+; RUN: opt %loadPolly -polly-scops -analyze -polly-delinearize < %s | FileCheck %s
+; This is a test that currently fails due to problems in the delinearization
+; XFAIL: *
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; This test case checks for array access functions where the order in which the
+; loop ivs appear in the array subscript does not follow the order of the
+; the loops in which they are defined. This (very common) case caused problems
+; in the delinearization pass.
+;
+; void foo(long n, long m, long o, double A[n][m][o]) {
+;
+;   for (long i = 0; i < n; i++)
+;     for (long j = 0; j < m; j++)
+;       for (long k = 0; k < o; k++)
+;         A[i][k][j] = 1.0;
+; }
+
+; CHECK: p0: %n
+; CHECK: p1: %m
+; CHECK: p2: %o
+; CHECK-NOT: p3
+;
+; CHECK: Domain
+; CHECK:   [n, m, o] -> { Stmt_for_k[i0, i1, i2] : i0 >= 0 and i0 <= -1 + n and i1 >= 0 and i1 <= -1 + m and i2 >= 0 and i2 <= -1 + o };
+; CHECK: Scattering
+; CHECK:   [n, m, o] -> { Stmt_for_k[i0, i1, i2] -> scattering[0, i0, 0, i1, 0, i2, 0] };
+; CHECK: WriteAccess
+; CHECK:   [n, m, o] -> { Stmt_for_k[i0, i1, i2] -> MemRef_A[i0, i2, i1] };
+
+define void @foo(i64 %n, i64 %m, i64 %o, double* %A) {
+entry:
+  br label %for.i
+
+for.i:
+  %i = phi i64 [ 0, %entry ], [ %i.inc, %for.i.inc ]
+  br label %for.j
+
+for.j:
+  %j = phi i64 [ 0, %for.i ], [ %j.inc, %for.j.inc ]
+  br label %for.k
+
+for.k:
+  %k = phi i64 [ 0, %for.j ], [ %k.inc, %for.k.inc ]
+  %subscript0 = mul i64 %i, %m
+  %subscript1 = add i64 %k, %subscript0
+  %subscript2 = mul i64 %subscript1, %o
+  %subscript = add i64 %subscript2, %j
+  %idx = getelementptr inbounds double* %A, i64 %subscript
+  store double 1.0, double* %idx
+  br label %for.k.inc
+
+for.k.inc:
+  %k.inc = add nsw i64 %k, 1
+  %k.exitcond = icmp eq i64 %k.inc, %o
+  br i1 %k.exitcond, label %for.j.inc, label %for.k
+
+for.j.inc:
+  %j.inc = add nsw i64 %j, 1
+  %j.exitcond = icmp eq i64 %j.inc, %m
+  br i1 %j.exitcond, label %for.i.inc, label %for.j
+
+for.i.inc:
+  %i.inc = add nsw i64 %i, 1
+  %i.exitcond = icmp eq i64 %i.inc, %n
+  br i1 %i.exitcond, label %end, label %for.i
+
+end:
+  ret void
+}