ARM: make sure FastISel bails on f64 operations for Cortex-M4.

FastISel wasn't checking the isFPOnlySP subtarget feature before emitting
double-precision operations, so it got completely invalid CodeGen for doubles
on Cortex-M4F.

The normal ISel testing wasn't spectacular either so I added a second RUN line
to improve that while I was in the area.

llvm-svn: 296031

Author: TNorthover

llvm/lib/Target/ARM/ARMFastISel.cpp

@@ -1350,8 +1350,10 @@ bool ARMFastISel::ARMEmitCmp(const Value *Src1Value, const Value *Src2Value,
   if (!SrcEVT.isSimple()) return false;
   MVT SrcVT = SrcEVT.getSimpleVT();
 
-  bool isFloat = (Ty->isFloatTy() || Ty->isDoubleTy());
-  if (isFloat && !Subtarget->hasVFP2())
+  if (Ty->isFloatTy() && !Subtarget->hasVFP2())
+    return false;
+
+  if (Ty->isDoubleTy() && (!Subtarget->hasVFP2() || Subtarget->isFPOnlySP()))
     return false;
 
   // Check to see if the 2nd operand is a constant that we can encode directly
@@ -1501,7 +1503,7 @@ bool ARMFastISel::SelectCmp(const Instruction *I) {
 
 bool ARMFastISel::SelectFPExt(const Instruction *I) {
   // Make sure we have VFP and that we're extending float to double.
-  if (!Subtarget->hasVFP2()) return false;
+  if (!Subtarget->hasVFP2() || Subtarget->isFPOnlySP()) return false;
 
   Value *V = I->getOperand(0);
   if (!I->getType()->isDoubleTy() ||
@@ -1520,7 +1522,7 @@ bool ARMFastISel::SelectFPExt(const Instruction *I) {
 
 bool ARMFastISel::SelectFPTrunc(const Instruction *I) {
   // Make sure we have VFP and that we're truncating double to float.
-  if (!Subtarget->hasVFP2()) return false;
+  if (!Subtarget->hasVFP2() || Subtarget->isFPOnlySP()) return false;
 
   Value *V = I->getOperand(0);
   if (!(I->getType()->isFloatTy() &&
@@ -1571,7 +1573,8 @@ bool ARMFastISel::SelectIToFP(const Instruction *I, bool isSigned) {
 
   unsigned Opc;
   if (Ty->isFloatTy()) Opc = isSigned ? ARM::VSITOS : ARM::VUITOS;
-  else if (Ty->isDoubleTy()) Opc = isSigned ? ARM::VSITOD : ARM::VUITOD;
+  else if (Ty->isDoubleTy() && !Subtarget->isFPOnlySP())
+    Opc = isSigned ? ARM::VSITOD : ARM::VUITOD;
   else return false;
 
   unsigned ResultReg = createResultReg(TLI.getRegClassFor(DstVT));
@@ -1596,7 +1599,8 @@ bool ARMFastISel::SelectFPToI(const Instruction *I, bool isSigned) {
   unsigned Opc;
   Type *OpTy = I->getOperand(0)->getType();
   if (OpTy->isFloatTy()) Opc = isSigned ? ARM::VTOSIZS : ARM::VTOUIZS;
-  else if (OpTy->isDoubleTy()) Opc = isSigned ? ARM::VTOSIZD : ARM::VTOUIZD;
+  else if (OpTy->isDoubleTy() && !Subtarget->isFPOnlySP())
+    Opc = isSigned ? ARM::VTOSIZD : ARM::VTOUIZD;
   else return false;
 
   // f64->s32/u32 or f32->s32/u32 both need an intermediate f32 reg.
@@ -1800,8 +1804,9 @@ bool ARMFastISel::SelectBinaryFPOp(const Instruction *I, unsigned ISDOpcode) {
   // if we have them.
   // FIXME: It'd be nice to use NEON instructions.
   Type *Ty = I->getType();
-  bool isFloat = (Ty->isDoubleTy() || Ty->isFloatTy());
-  if (isFloat && !Subtarget->hasVFP2())
+  if (Ty->isFloatTy() && !Subtarget->hasVFP2())
+    return false;
+  if (Ty->isDoubleTy() && (!Subtarget->hasVFP2() || Subtarget->isFPOnlySP()))
     return false;
 
   unsigned Opc;

llvm/test/CodeGen/ARM/fp-only-sp.ll

@@ -0,0 +1,62 @@
+; RUN: llc -mtriple=thumbv7em-apple-macho -mcpu=cortex-m4 %s -o - -O0 | FileCheck %s
+; RUN: llc -mtriple=thumbv7em-apple-macho -mcpu=cortex-m4 %s -o - | FileCheck %s
+
+; Note: vldr and vstr really do have 64-bit variants even with fp-only-sp
+define void @test_load_store(double* %addr) {
+; CHECK-LABEL: test_load_store:
+; CHECK: vldr [[TMP:d[0-9]+]], [r0]
+; CHECK: vstr [[TMP]], [r0]
+  %val = load volatile double, double* %addr
+  store volatile double %val, double* %addr
+  ret void
+}
+
+define void @test_cmp(double %l, double %r, i1* %addr.dst) {
+; CHECK-LABEL: test_cmp:
+; CHECK: bl ___eqdf2
+  %res = fcmp oeq double %l, %r
+  store i1 %res, i1* %addr.dst
+  ret void
+}
+
+define void @test_ext(float %in, double* %addr) {
+; CHECK-LABEL: test_ext:
+; CHECK: bl ___extendsfdf2
+  %res = fpext float %in to double
+  store double %res, double* %addr
+  ret void
+}
+
+define void @test_trunc(double %in, float* %addr) {
+; CHECK-LABEL: test_trunc:
+; CHECK: bl ___truncdfsf2
+  %res = fptrunc double %in to float
+  store float %res, float* %addr
+  ret void
+}
+
+define void @test_itofp(i32 %in, double* %addr) {
+; CHECK-LABEL: test_itofp:
+; CHECK: bl ___floatsidf
+  %res = sitofp i32 %in to double
+  store double %res, double* %addr
+;  %res = fptoui double %tmp to i32
+  ret void
+}
+
+define i32 @test_fptoi(double* %addr) {
+; CHECK-LABEL: test_fptoi:
+; CHECK: bl ___fixunsdfsi
+  %val = load double, double* %addr
+  %res = fptoui double %val to i32
+  ret i32 %res
+}
+
+define void @test_binop(double* %addr) {
+; CHECK-LABEL: test_binop:
+; CHECK: bl ___adddf3
+  %in = load double, double* %addr
+  %res = fadd double %in, %in
+  store double %res, double* %addr
+  ret void
+}