Issue diagnostics when returning FP values on x86_64 without SSE1/2

Avoid using report_fatal_error, because it will ask the user to file a
bug. If the user attempts to disable SSE on x86_64 and them use floating
point, that's a bug in their code, not a bug in the compiler.

This is just a start. There are other ways to crash the backend in this
configuration, but they should be updated to follow this pattern.

Differential Revision: https://reviews.llvm.org/D27522

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302835 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Reid Kleckner 2017-05-11 22:43:02 +00:00
parent d3fe6038ab
commit c627bffdd6

View File

@ -40,6 +40,7 @@
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
@ -79,6 +80,17 @@ static cl::opt<int> ExperimentalPrefLoopAlignment(
" of the loop header PC will be 0)."),
cl::Hidden);
/// Call this when the user attempts to do something unsupported, like
/// returning a double without SSE2 enabled on x86_64. This is not fatal, unlike
/// report_fatal_error, so calling code should attempt to recover without
/// crashing.
static void errorUnsupported(SelectionDAG &DAG, const SDLoc &dl,
const char *Msg) {
MachineFunction &MF = DAG.getMachineFunction();
DAG.getContext()->diagnose(
DiagnosticInfoUnsupported(*MF.getFunction(), Msg, dl.getDebugLoc()));
}
X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
const X86Subtarget &STI)
: TargetLowering(TM), Subtarget(STI) {
@ -2205,15 +2217,17 @@ X86TargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
// or SSE or MMX vectors.
if ((ValVT == MVT::f32 || ValVT == MVT::f64 ||
VA.getLocReg() == X86::XMM0 || VA.getLocReg() == X86::XMM1) &&
(Subtarget.is64Bit() && !Subtarget.hasSSE1())) {
report_fatal_error("SSE register return with SSE disabled");
(Subtarget.is64Bit() && !Subtarget.hasSSE1())) {
errorUnsupported(DAG, dl, "SSE register return with SSE disabled");
VA.convertToReg(X86::FP0); // Set reg to FP0, avoid hitting asserts.
} else if (ValVT == MVT::f64 &&
(Subtarget.is64Bit() && !Subtarget.hasSSE2())) {
// Likewise we can't return F64 values with SSE1 only. gcc does so, but
// llvm-gcc has never done it right and no one has noticed, so this
// should be OK for now.
errorUnsupported(DAG, dl, "SSE2 register return with SSE2 disabled");
VA.convertToReg(X86::FP0); // Set reg to FP0, avoid hitting asserts.
}
// Likewise we can't return F64 values with SSE1 only. gcc does so, but
// llvm-gcc has never done it right and no one has noticed, so this
// should be OK for now.
if (ValVT == MVT::f64 &&
(Subtarget.is64Bit() && !Subtarget.hasSSE2()))
report_fatal_error("SSE2 register return with SSE2 disabled");
// Returns in ST0/ST1 are handled specially: these are pushed as operands to
// the RET instruction and handled by the FP Stackifier.
@ -2526,7 +2540,8 @@ SDValue X86TargetLowering::LowerCallResult(
// If this is x86-64, and we disabled SSE, we can't return FP values
if ((CopyVT == MVT::f32 || CopyVT == MVT::f64 || CopyVT == MVT::f128) &&
((Is64Bit || Ins[InsIndex].Flags.isInReg()) && !Subtarget.hasSSE1())) {
report_fatal_error("SSE register return with SSE disabled");
errorUnsupported(DAG, dl, "SSE register return with SSE disabled");
VA.convertToReg(X86::FP0); // Set reg to FP0, avoid hitting asserts.
}
// If we prefer to use the value in xmm registers, copy it out as f80 and