From 85b93331b2660ca22cbb69b4e88d6190367968ff Mon Sep 17 00:00:00 2001
From: Eli Friedman <efriedma@codeaurora.org>
Date: Wed, 14 Jun 2017 22:43:28 +0000
Subject: [PATCH] Don't check side effects for functions outside of SCoP

In r304074 we introduce a patch to accept results from side effect free
functions into SCEV modeling. This causes rejection of cases where the
call is happening outside the SCoP. This patch checks if the call is
outside the Region and treats the results as a parameter (SCEVType::PARAM)
to the SCoP instead of returning SCEVType::INVALID.

Patch by Sameer Abu Asal.



git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@305423 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Support/SCEVValidator.cpp                      |  9 +++---
 .../constant_functions_outside_scop_as_unknown.ll  | 36 ++++++++++++++++++++++
 2 files changed, 41 insertions(+), 4 deletions(-)
 create mode 100644 test/ScopInfo/constant_functions_outside_scop_as_unknown.ll

diff --git a/lib/Support/SCEVValidator.cpp b/lib/Support/SCEVValidator.cpp
index 1941875d..36624242 100644
--- a/lib/Support/SCEVValidator.cpp
+++ b/lib/Support/SCEVValidator.cpp
@@ -320,11 +320,12 @@ public:
   ValidatorResult visitCallInstruction(Instruction *I, const SCEV *S) {
     assert(I->getOpcode() == Instruction::Call && "Call instruction expected");
 
-    auto Call = cast<CallInst>(I);
-
-    if (!isConstCall(Call))
-      return ValidatorResult(SCEVType::INVALID, S);
+    if (R->contains(I)) {
+      auto Call = cast<CallInst>(I);
 
+      if (!isConstCall(Call))
+        return ValidatorResult(SCEVType::INVALID, S);
+    }
     return ValidatorResult(SCEVType::PARAM, S);
   }
 
diff --git a/test/ScopInfo/constant_functions_outside_scop_as_unknown.ll b/test/ScopInfo/constant_functions_outside_scop_as_unknown.ll
new file mode 100644
index 00000000..6892c0e3
--- /dev/null
+++ b/test/ScopInfo/constant_functions_outside_scop_as_unknown.ll
@@ -0,0 +1,36 @@
+; RUN: opt -polly-process-unprofitable -polly-scops -analyze < %s | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+
+; CHECK: Region: %for.cond62---%for.cond
+; CHECK: p0: {0,+,1}<nuw><%for.cond>
+; CHECK-NEXT: p1: %param1
+; CHECK-NEXT: p2: %param2
+; CHECK-NEXT: Arrays {
+
+define void @f(i8* %param1) {
+entry:
+  br label %for.cond
+
+for.cond:
+  %hook = phi i8* [ %param1, %entry ], [ %add.ptr201, %cleanup ]
+  br i1 undef, label %for.body, label %for.cond.cleanup
+
+for.body:
+  %param2 = call i32 @g()
+  %add.ptr60 = getelementptr inbounds i8, i8* %hook, i32 %param2
+  br label %for.cond62
+
+for.cond62:
+  %cmp64 = icmp ule i8* %add.ptr60, null
+  br i1 %cmp64, label %for.cond62, label %cleanup
+
+cleanup:
+  %add.ptr201 = getelementptr inbounds i8, i8* %hook, i32 1
+  br label %for.cond
+
+for.cond.cleanup:
+  ret void
+}
+
+declare i32 @g()
-- 
2.11.4.GIT