[llvm] r212431 - ARM: properly lower dllimport'ed global values
Saleem Abdulrasool
compnerd at compnerd.org
Sun Jul 6 22:18:35 PDT 2014
Author: compnerd
Date: Mon Jul 7 00:18:35 2014
New Revision: 212431
URL: http://llvm.org/viewvc/llvm-project?rev=212431&view=rev
Log:
ARM: properly lower dllimport'ed global values
This completes the handling for DLL import storage symbols when lowering
instructions. A DLL import storage symbol must have an additional load
performed prior to use. This is applicable to variables and functions.
This is particularly important for non-function symbols as it is possible to
handle function references by emitting a thunk which performs the translation
from the unprefixed __imp_ symbol to the proper symbol (although, this is a
non-optimal lowering). For a variable symbol, no such thunk can be
accommodated.
Added:
llvm/trunk/test/CodeGen/ARM/Windows/dllimport.ll
Modified:
llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp?rev=212431&r1=212430&r2=212431&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp Mon Jul 7 00:18:35 2014
@@ -1654,6 +1654,19 @@ ARMTargetLowering::LowerCall(TargetLower
assert(Subtarget->isTargetMachO() && "WrapperPIC use on non-MachO?");
Callee = DAG.getNode(ARMISD::WrapperPIC, dl, getPointerTy(),
DAG.getTargetGlobalAddress(GV, dl, getPointerTy()));
+ } else if (Subtarget->isTargetCOFF()) {
+ assert(Subtarget->isTargetWindows() &&
+ "Windows is the only supported COFF target");
+ unsigned TargetFlags = GV->hasDLLImportStorageClass()
+ ? ARMII::MO_DLLIMPORT
+ : ARMII::MO_NO_FLAG;
+ Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(), /*Offset=*/0,
+ TargetFlags);
+ if (GV->hasDLLImportStorageClass())
+ Callee = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(),
+ DAG.getNode(ARMISD::Wrapper, dl, getPointerTy(),
+ Callee), MachinePointerInfo::getGOT(),
+ false, false, false, 0);
} else {
// On ELF targets for PIC code, direct calls should go through the PLT
unsigned OpFlags = 0;
@@ -2489,15 +2502,23 @@ SDValue ARMTargetLowering::LowerGlobalAd
"Windows on ARM expects to use movw/movt");
const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
+ const ARMII::TOF TargetFlags =
+ (GV->hasDLLImportStorageClass() ? ARMII::MO_DLLIMPORT : ARMII::MO_NO_FLAG);
EVT PtrVT = getPointerTy();
+ SDValue Result;
SDLoc DL(Op);
++NumMovwMovt;
// FIXME: Once remat is capable of dealing with instructions with register
// operands, expand this into two nodes.
- return DAG.getNode(ARMISD::Wrapper, DL, PtrVT,
- DAG.getTargetGlobalAddress(GV, DL, PtrVT));
+ Result = DAG.getNode(ARMISD::Wrapper, DL, PtrVT,
+ DAG.getTargetGlobalAddress(GV, DL, PtrVT, /*Offset=*/0,
+ TargetFlags));
+ if (GV->hasDLLImportStorageClass())
+ Result = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), Result,
+ MachinePointerInfo::getGOT(), false, false, false, 0);
+ return Result;
}
SDValue ARMTargetLowering::LowerGLOBAL_OFFSET_TABLE(SDValue Op,
Added: llvm/trunk/test/CodeGen/ARM/Windows/dllimport.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/Windows/dllimport.ll?rev=212431&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/Windows/dllimport.ll (added)
+++ llvm/trunk/test/CodeGen/ARM/Windows/dllimport.ll Mon Jul 7 00:18:35 2014
@@ -0,0 +1,61 @@
+; RUN: llc -mtriple thumbv7-windows -filetype asm -o - %s | FileCheck %s
+
+; ModuleID = 'dllimport.c'
+
+ at var = external dllimport global i32
+ at ext = external global i32
+declare dllimport arm_aapcs_vfpcc i32 @external()
+declare arm_aapcs_vfpcc i32 @internal()
+
+define arm_aapcs_vfpcc i32 @get_var() {
+ %1 = load i32* @var, align 4
+ ret i32 %1
+}
+
+; CHECK-LABEL: get_var
+; CHECK: movw r0, :lower16:__imp_var
+; CHECK: movt r0, :upper16:__imp_var
+; CHECK: ldr r0, [r0]
+; CHECK: ldr r0, [r0]
+; CHECK: bx lr
+
+define arm_aapcs_vfpcc i32 @get_ext() {
+ %1 = load i32* @ext, align 4
+ ret i32 %1
+}
+
+; CHECK-LABEL: get_ext
+; CHECK: movw r0, :lower16:ext
+; CHECK: movt r0, :upper16:ext
+; CHECK: ldr r0, [r0]
+; CHECK: bx lr
+
+define arm_aapcs_vfpcc i32* @get_var_pointer() {
+ ret i32* @var
+}
+
+; CHECK-LABEL: get_var_pointer
+; CHECK: movw r0, :lower16:__imp_var
+; CHECK: movt r0, :upper16:__imp_var
+; CHECK: ldr r0, [r0]
+; CHECK: bx lr
+
+define arm_aapcs_vfpcc i32 @call_external() {
+ %call = tail call arm_aapcs_vfpcc i32 @external()
+ ret i32 %call
+}
+
+; CHECK-LABEL: call_external
+; CHECK: movw r0, :lower16:__imp_external
+; CHECK: movt r0, :upper16:__imp_external
+; CHECK: ldr r0, [r0]
+; CHECK: bx r0
+
+define arm_aapcs_vfpcc i32 @call_internal() {
+ %call = tail call arm_aapcs_vfpcc i32 @internal()
+ ret i32 %call
+}
+
+; CHECK-LABEL: call_internal
+; CHECK: b internal
+
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