[Polly] [Failing test case] Add test case that seems to fail due to invalid referencing of instructions across host and kernel modules.

[bollu]

• remove invariant load hoisting

[bollu]

• [NFC] make test case understandable

[bollu]

• [Works] [WIP] recreate whatever IslNodeBuilder does in PPCGCodeGeneration

[bollu]

This is being solved in D36290, so I'm closing this.

test/GPGPU/test.ll

+; RUN: opt %loadPolly -polly-codegen-ppcg -polly-acc-fail-on-verify-module-failure \
+; RUN: -disable-output < %s
+
+; ModuleID = 'reduced.ll'
+source_filename = "bugpoint-output-cb5513b.bc"
+target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare void @fn_to_fence(i32 *%val)
+
+
+; void f(int *arr, bool shouldcont) {
+;     for(int i = 0; ; i++) {
+;         for(int j = 0; j < 10; j++) {
+;             arr[j] = i;
+;         }
+;         fence(arr);
+;         if (!shouldcont) break;
+;     }
+; }
+
+
+; Function Attrs: nounwind uwtable
+define void @f(i32 *%arr, i1 %shouldcont) #1 {
+entry:
+  br label %for.init
+
+for.init:                                             ; preds = %for.end, %entry.split
+  %indvar = phi i32 [ %indvar.next, %for.end ], [ 0, %entry ]
+  br label %for2.body
+
+for2.body:                                             ; preds = %"65", %"64"
+  %indvar2 = phi i32 [ %indvar2.next, %for2.body ], [ 0, %for.init ]
+  %indvar2.sext = sext i32 %indvar2 to i64
+  %arr.slot = getelementptr i32, i32* %arr, i64 %indvar2.sext
+  store i32 %indvar, i32* %arr.slot, align 4
+  %exitcond = icmp eq i32 %indvar2, 10
+  %indvar2.next = add i32 %indvar2, 1
+  br i1 %exitcond, label %for2.body.fence, label %for2.body
+
+for2.body.fence:                                             ; preds = %"65"
+  call void @fn_to_fence(i32* %arr) #2
+  br i1 %shouldcont, label %for.end, label %exit
+for.end:                                             ; preds = %"69"
+  %indvar.next = add i32 %indvar, 1
+  br label %for.init
+
+exit:                                             ; preds = %"69"
+  ret void
+
+}
+
+; Function Attrs: nounwind
+declare noalias i8* @malloc(i64) #2
+
+declare void @used_fn(...)
+
+
+attributes #0 = { argmemonly nounwind }
+attributes #1 = { nounwind uwtable }
+attributes #2 = { nounwind }