[MIPS] Fix illegal type assert in single-float mode

An fp_to_sint node would be incorrectly lowered to a TruncIntFP node in
single-float mode. This would trigger an "Unexpected illegal type!"
assert.

Patch by Dan Ravensloft.

Differential revision: https://reviews.llvm.org/D51810

llvm-svn: 341952

2 files changed, 60 insertions, 3 deletions

diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index 0677d378a11..104fa4090ec 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -2563,10 +2563,12 @@ static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
 }
 
 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
-static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG) {
+static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
+                                     bool SingleFloat) {
   SDValue Val = SD->getValue();
 
-  if (Val.getOpcode() != ISD::FP_TO_SINT)
+  if (Val.getOpcode() != ISD::FP_TO_SINT ||
+      (Val.getValueSizeInBits() > 32 && SingleFloat))
     return SDValue();
 
   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
@@ -2587,7 +2589,7 @@ SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
 
-  return lowerFP_TO_SINT_STORE(SD, DAG);
+  return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
 }
 
 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
@@ -2603,6 +2605,9 @@ SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
 
 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
                                             SelectionDAG &DAG) const {
+  if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
+    return SDValue();
+
   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
                               Op.getOperand(0));
diff --git a/llvm/test/CodeGen/Mips/f32-to-i64-single-float.ll b/llvm/test/CodeGen/Mips/f32-to-i64-single-float.ll
new file mode 100644
index 00000000000..47d86f57e0c
--- /dev/null
+++ b/llvm/test/CodeGen/Mips/f32-to-i64-single-float.ll
@@ -0,0 +1,52 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=mips64el-mti-linux-gnu -mattr=+single-float < %s | FileCheck %s
+; This test casts a 32-bit float to a 64-bit int. This would cause a crash due
+; to LLVM incorrectly lowering the float on single-float platforms.
+
+define void @foo(float* %in, i64* %out) {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    daddiu $sp, $sp, -16
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    sd $5, 0($sp)
+; CHECK-NEXT:    sd $4, 8($sp)
+; CHECK-NEXT:    lwc1 $f0, 0($4)
+; CHECK-NEXT:    mfc1 $1, $f0
+; CHECK-NEXT:    lui $2, 32640
+; CHECK-NEXT:    and $2, $1, $2
+; CHECK-NEXT:    srl $2, $2, 23
+; CHECK-NEXT:    lui $3, 127
+; CHECK-NEXT:    ori $3, $3, 65535
+; CHECK-NEXT:    addiu $4, $zero, 150
+; CHECK-NEXT:    subu $4, $4, $2
+; CHECK-NEXT:    and $3, $1, $3
+; CHECK-NEXT:    lui $6, 128
+; CHECK-NEXT:    or $3, $3, $6
+; CHECK-NEXT:    dsll $3, $3, 32
+; CHECK-NEXT:    dsrl $3, $3, 32
+; CHECK-NEXT:    dsrlv $4, $3, $4
+; CHECK-NEXT:    addiu $6, $2, -150
+; CHECK-NEXT:    dsllv $3, $3, $6
+; CHECK-NEXT:    addiu $2, $2, -127
+; CHECK-NEXT:    slti $6, $2, 24
+; CHECK-NEXT:    movz $4, $3, $6
+; CHECK-NEXT:    sra $1, $1, 31
+; CHECK-NEXT:    xor $3, $4, $1
+; CHECK-NEXT:    dsubu $1, $3, $1
+; CHECK-NEXT:    slti $2, $2, 0
+; CHECK-NEXT:    movn $1, $zero, $2
+; CHECK-NEXT:    sd $1, 0($5)
+; CHECK-NEXT:    jr $ra
+; CHECK-NEXT:    daddiu $sp, $sp, 16
+entry:
+  %in.addr = alloca float*, align 8
+  %out.addr = alloca i64*, align 8
+  store float* %in, float** %in.addr, align 8
+  store i64* %out, i64** %out.addr, align 8
+  %0 = load float*, float** %in.addr, align 8
+  %1 = load float, float* %0, align 4
+  %conv = fptosi float %1 to i64
+  %2 = load i64*, i64** %out.addr, align 8
+  store i64 %conv, i64* %2, align 8
+  ret void
+}