Enable FastISel on ARM for Linux and NaCl
FastISel was only enabled for iOS ARM and Thumb2, this patch enables it
for ARM (not Thumb2) on Linux and NaCl.
Thumb2 support needs a bit more work, mainly around register class
restrictions.
The patch punts to SelectionDAG when doing TLS relocation on non-Darwin
targets. I will fix this and other FastISel-to-SelectionDAG failures in
a separate patch.
The patch also forces FastISel to retain frame pointers: iOS always
keeps them for backtracking (so emitted code won't change because of
this), but Linux was getting much worse code that was incorrect when
using big frames (such as test-suite's lencod). I'll also fix this in a
later patch, it will probably require a peephole so that FastISel
doesn't rematerialize frame pointers back-to-back.
The test changes are straightforward, similar to:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130513/174279.html
They also add a vararg test that got dropped in that change.
I ran all of test-suite on A15 hardware with --optimize-option=-O0 and
all the tests pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182877 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 1c3fa84..a647688 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -628,6 +628,11 @@
(const TargetRegisterClass*)&ARM::GPRRegClass;
unsigned DestReg = createResultReg(RC);
+ // FastISel TLS support on non-Darwin is broken, punt to SelectionDAG.
+ const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
+ bool IsThreadLocal = GVar && GVar->isThreadLocal();
+ if (!Subtarget->isTargetDarwin() && IsThreadLocal) return 0;
+
// Use movw+movt when possible, it avoids constant pool entries.
// Darwin targets don't support movt with Reloc::Static, see
// ARMTargetLowering::LowerGlobalAddressDarwin. Other targets only support
@@ -2961,13 +2966,22 @@
namespace llvm {
FastISel *ARM::createFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo) {
- // Completely untested on non-iOS.
const TargetMachine &TM = funcInfo.MF->getTarget();
- // Darwin and thumb1 only for now.
const ARMSubtarget *Subtarget = &TM.getSubtarget<ARMSubtarget>();
- if (Subtarget->isTargetIOS() && !Subtarget->isThumb1Only())
+ // Thumb2 support on iOS; ARM support on iOS, Linux and NaCl.
+ bool UseFastISel = false;
+ UseFastISel |= Subtarget->isTargetIOS() && !Subtarget->isThumb1Only();
+ UseFastISel |= Subtarget->isTargetLinux() && !Subtarget->isThumb();
+ UseFastISel |= Subtarget->isTargetNaCl() && !Subtarget->isThumb();
+ if (UseFastISel) {
+ // iOS always has a FP for backtracking, force other targets
+ // to keep their FP when doing FastISel. The emitted code is
+ // currently superior, and in cases like test-suite's lencod
+ // FastISel isn't quite correct when FP is eliminated.
+ TM.Options.NoFramePointerElim = true;
return new ARMFastISel(funcInfo, libInfo);
+ }
return 0;
}
}