[GlobalOpt] Check if global gets compared to pointer of different obj.

llvm/lib/Transforms/Utils/GlobalStatus.cpp

@@ -8,6 +8,7 @@
 
 #include "llvm/Transforms/Utils/GlobalStatus.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
@@ -17,6 +18,7 @@
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/PatternMatch.h"
 #include "llvm/IR/Use.h"
 #include "llvm/IR/User.h"
 #include "llvm/IR/Value.h"
@@ -26,6 +28,7 @@
 #include <cassert>
 
 using namespace llvm;
+using namespace llvm::PatternMatch;
 
 /// Return the stronger of the two ordering. If the two orderings are acquire
 /// and release, then return AcquireRelease.
@@ -158,6 +161,17 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
             return true;
       } else if (isa<CmpInst>(I)) {
         GS.IsCompared = true;
+
+        const Value *UO = nullptr;
+        for (Value *Op : I->operands()) {
+          if (match(Op, m_Zero()))
+            continue;
+          const Value *OpUO = getUnderlyingObject(Op);
+          if (!UO)
+            UO = OpUO;
+          if (!OpUO || UO != OpUO)
+            return true;
+        }
       } else if (const MemTransferInst *MTI = dyn_cast<MemTransferInst>(I)) {
         if (MTI->isVolatile())
           return true;

llvm/test/Transforms/GlobalOpt/globals-compares-with-ptrtoint.ll

@@ -0,0 +1,173 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5
+; RUN: opt -p globalopt -S %s | FileCheck %s
+
+@A = internal global i64 zeroinitializer
+@B = internal global i64 zeroinitializer
+
+@C = internal global i64 zeroinitializer
+@D = internal global i64 zeroinitializer
+
+@E = internal global i64 zeroinitializer
+@F = internal global i64 zeroinitializer
+
+@G = internal global i64 zeroinitializer
+@H = internal global i64 zeroinitializer
+
+@J = internal global [2 x ptr] zeroinitializer
+
+;.
+; CHECK: @A = internal global i64 0
+; CHECK: @B = internal global i64 0
+; CHECK: @C = internal global i64 0
+; CHECK: @D = internal global i64 0
+; CHECK: @G = internal global i64 0
+; CHECK: @H = internal global i64 0
+; CHECK: @J = internal global [2 x ptr] zeroinitializer
+;.
+define i64 @A_and_B_cmp_ptrtoint_constant_expr() {
+; CHECK-LABEL: define i64 @A_and_B_cmp_ptrtoint_constant_expr() local_unnamed_addr {
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq ptr inttoptr (i64 add (i64 ptrtoint (ptr @A to i64), i64 8) to ptr), @B
+; CHECK-NEXT:    br i1 [[CMP]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @A to i64), i64 8) to ptr), align 4
+; CHECK-NEXT:    br label %[[EXIT:.*]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[L:%.*]] = load i64, ptr @B, align 4
+; CHECK-NEXT:    ret i64 [[L]]
+;
+  %cmp = icmp eq ptr inttoptr (i64 add (i64 ptrtoint (ptr @A to i64), i64 8) to ptr) , @B
+  br i1 %cmp, label %then, label %else
+
+then:
+  store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @A to i64), i64 8) to ptr)
+  br label %exit
+
+else:
+  br label %exit
+
+exit:
+  %l = load i64, ptr @B
+  ret i64 %l
+}
+
+define i64 @G_and_H_cmp_ptrtoint_constant_expr_cmp_ops_swapped() {
+; CHECK-LABEL: define i64 @G_and_H_cmp_ptrtoint_constant_expr_cmp_ops_swapped() local_unnamed_addr {
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq ptr inttoptr (i64 add (i64 ptrtoint (ptr @G to i64), i64 8) to ptr), @H
+; CHECK-NEXT:    br i1 [[CMP]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @G to i64), i64 8) to ptr), align 4
+; CHECK-NEXT:    br label %[[EXIT:.*]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[L:%.*]] = load i64, ptr @H, align 4
+; CHECK-NEXT:    ret i64 [[L]]
+;
+  %cmp = icmp eq ptr inttoptr (i64 add (i64 ptrtoint (ptr @G to i64), i64 8) to ptr) , @H
+  br i1 %cmp, label %then, label %else
+
+then:
+  store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @G to i64), i64 8) to ptr)
+  br label %exit
+
+else:
+  br label %exit
+
+exit:
+  %l = load i64, ptr @H
+  ret i64 %l
+}
+
+define i64 @C_and_D_cmp_ptr_load() {
+; CHECK-LABEL: define i64 @C_and_D_cmp_ptr_load() local_unnamed_addr {
+; CHECK-NEXT:    [[P:%.*]] = alloca ptr, align 8
+; CHECK-NEXT:    store ptr inttoptr (i64 add (i64 ptrtoint (ptr @C to i64), i64 8) to ptr), ptr [[P]], align 8
+; CHECK-NEXT:    [[L_P:%.*]] = load ptr, ptr [[P]], align 8
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq ptr [[L_P]], @D
+; CHECK-NEXT:    br i1 [[CMP]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @C to i64), i64 8) to ptr), align 4
+; CHECK-NEXT:    br label %[[EXIT:.*]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[L:%.*]] = load i64, ptr @D, align 4
+; CHECK-NEXT:    ret i64 [[L]]
+;
+  %p = alloca ptr
+  store ptr inttoptr (i64 add (i64 ptrtoint (ptr @C to i64), i64 8) to ptr), ptr %p
+  %l.p = load ptr, ptr %p
+  %cmp = icmp eq ptr %l.p, @D
+  br i1 %cmp, label %then, label %else
+
+then:
+  store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @C to i64), i64 8) to ptr)
+  br label %exit
+
+else:
+  br label %exit
+
+exit:
+  %l = load i64, ptr @D
+  ret i64 %l
+}
+
+define i64 @D_and_E_cmp_ptrtoint_constant_expr() {
+; CHECK-LABEL: define i64 @D_and_E_cmp_ptrtoint_constant_expr() local_unnamed_addr {
+; CHECK-NEXT:    [[PTR2INT:%.*]] = ptrtoint ptr @A to i64
+; CHECK-NEXT:    [[ADD:%.*]] = add i64 [[PTR2INT]], 8
+; CHECK-NEXT:    [[INT2PTR:%.*]] = inttoptr i64 [[ADD]] to ptr
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq ptr [[INT2PTR]], @B
+; CHECK-NEXT:    br i1 [[CMP]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @A to i64), i64 8) to ptr), align 4
+; CHECK-NEXT:    br label %[[EXIT:.*]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[L:%.*]] = load i64, ptr @B, align 4
+; CHECK-NEXT:    ret i64 [[L]]
+;
+  %ptr2int = ptrtoint ptr @A to i64
+  %add = add i64 %ptr2int, 8
+  %int2ptr = inttoptr i64 %add to ptr
+  %cmp = icmp eq ptr %int2ptr , @B
+  br i1 %cmp, label %then, label %else
+
+then:
+  store i64 10, ptr inttoptr (i64 add (i64 ptrtoint (ptr @A to i64), i64 8) to ptr)
+  br label %exit
+
+else:
+  br label %exit
+
+exit:
+  %l = load i64, ptr @B
+  ret i64 %l
+}
+
+define ptr @compare_arg(ptr %a) {
+; CHECK-LABEL: define ptr @compare_arg(
+; CHECK-SAME: ptr [[A:%.*]]) local_unnamed_addr {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[A]], @J
+; CHECK-NEXT:    br i1 [[C]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    [[L:%.*]] = load ptr, ptr @J, align 8
+; CHECK-NEXT:    ret ptr [[L]]
+; CHECK:       [[ELSE]]:
+; CHECK-NEXT:    ret ptr null
+;
+entry:
+  %c = icmp eq ptr %a, @J
+  br i1 %c, label %then, label %else
+
+then:
+  %l = load ptr, ptr @J, align 8
+  ret ptr %l
+
+else:
+  ret ptr null
+}