/// This GV is a pointer root. Loop over all users of the global and clean up
/// any that obviously don't assign the global a value that isn't dynamically
/// allocated.
-static bool CleanupPointerRootUsers(Value *V,
+static bool CleanupPointerRootUsers(GlobalVariable *GV,
const TargetLibraryInfo *TLI) {
// A brief explanation of leak checkers. The goal is to find bugs where
// pointers are forgotten, causing an accumulating growth in memory
SmallVector<std::pair<Instruction *, Instruction *>, 32> Dead;
// Constants can't be pointers to dynamically allocated memory.
- for (Value::user_iterator UI = V->user_begin(), E = V->user_end();
+ for (Value::user_iterator UI = GV->user_begin(), E = GV->user_end();
UI != E;) {
User *U = *UI++;
if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
Dead.push_back(std::make_pair(I, MTI));
}
} else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U)) {
- if (CE->getOpcode() == Instruction::GetElementPtr) {
- Changed |= CleanupPointerRootUsers(CE, TLI);
- }
if (CE->use_empty()) {
CE->destroyConstant();
Changed = true;
C->destroyConstant();
// This could have invalidated UI, start over from scratch.
Dead.clear();
- CleanupPointerRootUsers(V, TLI);
+ CleanupPointerRootUsers(GV, TLI);
return true;
}
}
[](User *UU) { return isSafeSROAElementUse(UU); });
}
-/// Return true if the specified GEP is a safe user of a derived
-/// expression from a global that we want to SROA.
-static bool isSafeSubSROAGEP(User *U) {
-
- // Check to see if this ConstantExpr GEP is SRA'able. In particular, we
- // don't like < 3 operand CE's, and we don't like non-constant integer
- // indices. This enforces that all uses are 'gep GV, 0, C, ...' for some
- // value of C.
- if (U->getNumOperands() < 3 || !isa<Constant>(U->getOperand(1)) ||
- !cast<Constant>(U->getOperand(1))->isNullValue())
- return false;
-
- return llvm::all_of(U->users(),
- [](User *UU) { return isSafeSROAElementUse(UU); });
-}
-
/// Return true if the specified instruction is a safe user of a derived
/// expression from a global that we want to SROA.
static bool isSafeSROAElementUse(Value *V) {
return SI->getOperand(0) != V;
// Otherwise, it must be a GEP. Check it and its users are safe to SRA.
- return isa<GetElementPtrInst>(I) && isSafeSubSROAGEP(I);
+ return isa<GetElementPtrInst>(I) && isSafeSROAGEP(I);
}
/// Look at all uses of the global and decide whether it is safe for us to
target triple = "x86_64-unknown-linux-gnu"
@g_data = internal unnamed_addr global <{ [8 x i16], [8 x i16] }> <{ [8 x i16] [i16 16, i16 16, i16 16, i16 16, i16 16, i16 16, i16 16, i16 16], [8 x i16] zeroinitializer }>, align 16
-; We normally cannot SRA here due to the second gep meaning the access to g_data may be to either element,
-; unless the value is always zero.
-; CHECK: @g_data.0 = internal unnamed_addr constant [8 x i16] [i16 16, i16 16, i16 16, i16 16, i16 16, i16 16, i16 16, i16 16], align 16
+; We cannot SRA here due to the second gep meaning the access to g_data may be to either element
+; CHECK: @g_data = internal unnamed_addr constant <{ [8 x i16], [8 x i16] }>
define i16 @test(i64 %a1) {
entry:
%g1 = getelementptr inbounds <{ [8 x i16], [8 x i16] }>, <{ [8 x i16], [8 x i16] }>* @g_data, i64 0, i32 0
%arrayidx.i = getelementptr inbounds [8 x i16], [8 x i16]* %g1, i64 0, i64 %a1
%r = load i16, i16* %arrayidx.i, align 2
-
-; CHECK-NOT: getelementptr inbounds <{ [8 x i16], [8 x i16] }>, <{ [8 x i16], [8 x i16] }>* @g_data, i64 0, i32 0
-; CHECK: %arrayidx.i = getelementptr inbounds [8 x i16], [8 x i16]* @g_data.0, i64 0, i64 %a1
-
ret i16 %r
-
-
}
+++ /dev/null
-; RUN: opt < %s -globalopt -S | FileCheck %s
-
-%struct.Expr = type { [1 x i32], i32 }
-
-@e = internal global %struct.Expr zeroinitializer, align 4
-; CHECK-NOT: @e = internal global %struct.Expr zeroinitializer, align 4
-
-define dso_local i32 @foo(i32 %i) {
-entry:
- %i.addr = alloca i32, align 4
- store i32 %i, i32* %i.addr, align 4
- %0 = load i32, i32* %i.addr, align 4
- %arrayidx = getelementptr inbounds [1 x i32], [1 x i32]* getelementptr inbounds (%struct.Expr, %struct.Expr* @e, i32 0, i32 0), i32 0, i32 %0
- store i32 57005, i32* %arrayidx, align 4
- %1 = load i32, i32* getelementptr inbounds (%struct.Expr, %struct.Expr* @e, i32 0, i32 1), align 4
- ret i32 %1
-; CHECK: ret i32 0
-}