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Updating the x64 casting behavior to be IEEE 754 compliant and to use saturation for overflow #82781

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Updating the x64 casting behavior to be IEEE 754 compliant and to use saturation for overflow #82781

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54f00d7
Updating the RyuJIT casting behavior to be IEEE 754 compliant and to …
tannergooding Feb 19, 2022
eca9fa9
Updating Mono casting behavior to be IEEE 754 compliant and to satura…
tannergooding Feb 19, 2022
50cc3bf
Fix a test that depended on the old floating-point cast behavior
tannergooding Mar 1, 2023
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28 changes: 18 additions & 10 deletions docs/design/coreclr/botr/readytorun-format.md
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Expand Up @@ -810,8 +810,8 @@ enum ReadyToRunHelper
READYTORUN_HELPER_LLsh = 0xC7,
READYTORUN_HELPER_LRsh = 0xC8,
READYTORUN_HELPER_LRsz = 0xC9,
READYTORUN_HELPER_Lng2Dbl = 0xCA,
READYTORUN_HELPER_ULng2Dbl = 0xCB,
READYTORUN_HELPER_Int64ToDouble = 0xCA,
READYTORUN_HELPER_UInt64ToDouble = 0xCB,

// 32-bit division helpers
READYTORUN_HELPER_Div = 0xCC,
Expand All @@ -820,14 +820,22 @@ enum ReadyToRunHelper
READYTORUN_HELPER_UMod = 0xCF,

// Floating point conversions
READYTORUN_HELPER_Dbl2Int = 0xD0,
READYTORUN_HELPER_Dbl2IntOvf = 0xD1,
READYTORUN_HELPER_Dbl2Lng = 0xD2,
READYTORUN_HELPER_Dbl2LngOvf = 0xD3,
READYTORUN_HELPER_Dbl2UInt = 0xD4,
READYTORUN_HELPER_Dbl2UIntOvf = 0xD5,
READYTORUN_HELPER_Dbl2ULng = 0xD6,
READYTORUN_HELPER_Dbl2ULngOvf = 0xD7,
READYTORUN_HELPER_DoubleToInt32 = 0xD0,
READYTORUN_HELPER_DoubleToInt32Ovf = 0xD1,
READYTORUN_HELPER_DoubleToInt64 = 0xD2,
READYTORUN_HELPER_DoubleToInt64Ovf = 0xD3,
READYTORUN_HELPER_DoubleToUInt32 = 0xD4,
READYTORUN_HELPER_DoubleToUInt32Ovf = 0xD5,
READYTORUN_HELPER_DoubleToUInt64 = 0xD6,
READYTORUN_HELPER_DoubleToUInt64Ovf = 0xD7,
READYTORUN_HELPER_DoubleToInt8 = 0xD8,
READYTORUN_HELPER_DoubleToInt8Ovf = 0xD9,
READYTORUN_HELPER_DoubleToInt16 = 0xDA,
READYTORUN_HELPER_DoubleToInt16Ovf = 0xDB,
READYTORUN_HELPER_DoubleToUInt8 = 0xDC,
READYTORUN_HELPER_DoubleToUInt8Ovf = 0xDD,
READYTORUN_HELPER_DoubleToUInt16 = 0xDE,
READYTORUN_HELPER_DoubleToUInt16Ovf = 0xDF,

// Floating point ops
READYTORUN_HELPER_DblRem = 0xE0,
Expand Down
28 changes: 18 additions & 10 deletions src/coreclr/inc/corinfo.h
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Expand Up @@ -385,16 +385,24 @@ enum CorInfoHelpFunc
CORINFO_HELP_LMOD,
CORINFO_HELP_ULDIV,
CORINFO_HELP_ULMOD,
CORINFO_HELP_LNG2DBL, // Convert a signed int64 to a double
CORINFO_HELP_ULNG2DBL, // Convert a unsigned int64 to a double
CORINFO_HELP_DBL2INT,
CORINFO_HELP_DBL2INT_OVF,
CORINFO_HELP_DBL2LNG,
CORINFO_HELP_DBL2LNG_OVF,
CORINFO_HELP_DBL2UINT,
CORINFO_HELP_DBL2UINT_OVF,
CORINFO_HELP_DBL2ULNG,
CORINFO_HELP_DBL2ULNG_OVF,
CORINFO_HELP_Int64ToDouble,
CORINFO_HELP_UInt64ToDouble,
CORINFO_HELP_DoubleToInt8,
CORINFO_HELP_DoubleToInt8_OVF,
CORINFO_HELP_DoubleToInt16,
CORINFO_HELP_DoubleToInt16_OVF,
CORINFO_HELP_DoubleToInt32,
CORINFO_HELP_DoubleToInt32_OVF,
CORINFO_HELP_DoubleToInt64,
CORINFO_HELP_DoubleToInt64_OVF,
CORINFO_HELP_DoubleToUInt8,
CORINFO_HELP_DoubleToUInt8_OVF,
CORINFO_HELP_DoubleToUInt16,
CORINFO_HELP_DoubleToUInt16_OVF,
CORINFO_HELP_DoubleToUInt32,
CORINFO_HELP_DoubleToUInt32_OVF,
CORINFO_HELP_DoubleToUInt64,
CORINFO_HELP_DoubleToUInt64_OVF,
CORINFO_HELP_FLTREM,
CORINFO_HELP_DBLREM,
CORINFO_HELP_FLTROUND,
Expand Down
30 changes: 18 additions & 12 deletions src/coreclr/inc/jithelpers.h
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Expand Up @@ -35,8 +35,6 @@
JITHELPER(CORINFO_HELP_UDIV, JIT_UDiv, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_UMOD, JIT_UMod, CORINFO_HELP_SIG_8_STACK)

// CORINFO_HELP_DBL2INT, CORINFO_HELP_DBL2UINT, and CORINFO_HELP_DBL2LONG get
// patched for CPUs that support SSE2 (P4 and above).
#ifndef TARGET_64BIT
JITHELPER(CORINFO_HELP_LLSH, JIT_LLsh, CORINFO_HELP_SIG_REG_ONLY)
JITHELPER(CORINFO_HELP_LRSH, JIT_LRsh, CORINFO_HELP_SIG_REG_ONLY)
Expand All @@ -53,16 +51,24 @@
JITHELPER(CORINFO_HELP_LMOD, JIT_LMod, CORINFO_HELP_SIG_16_STACK)
JITHELPER(CORINFO_HELP_ULDIV, JIT_ULDiv, CORINFO_HELP_SIG_16_STACK)
JITHELPER(CORINFO_HELP_ULMOD, JIT_ULMod, CORINFO_HELP_SIG_16_STACK)
JITHELPER(CORINFO_HELP_LNG2DBL, JIT_Lng2Dbl, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_ULNG2DBL, JIT_ULng2Dbl, CORINFO_HELP_SIG_8_STACK)
DYNAMICJITHELPER(CORINFO_HELP_DBL2INT, JIT_Dbl2Lng, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DBL2INT_OVF, JIT_Dbl2IntOvf, CORINFO_HELP_SIG_8_STACK)
DYNAMICJITHELPER(CORINFO_HELP_DBL2LNG, JIT_Dbl2Lng, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DBL2LNG_OVF, JIT_Dbl2LngOvf, CORINFO_HELP_SIG_8_STACK)
DYNAMICJITHELPER(CORINFO_HELP_DBL2UINT, JIT_Dbl2Lng, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DBL2UINT_OVF, JIT_Dbl2UIntOvf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DBL2ULNG, JIT_Dbl2ULng, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DBL2ULNG_OVF, JIT_Dbl2ULngOvf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_Int64ToDouble, JIT_Int64ToDouble, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_UInt64ToDouble, JIT_UInt64ToDouble, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt8, JIT_DoubleToInt8, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt8_OVF, JIT_DoubleToInt8Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt16, JIT_DoubleToInt16, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt16_OVF, JIT_DoubleToInt16Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt32, JIT_DoubleToInt32, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt32_OVF, JIT_DoubleToInt32Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt64, JIT_DoubleToInt64, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToInt64_OVF, JIT_DoubleToInt64Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt8, JIT_DoubleToUInt8, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt8_OVF, JIT_DoubleToUInt8Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt16, JIT_DoubleToUInt16, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt16_OVF, JIT_DoubleToUInt16Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt32, JIT_DoubleToUInt32, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt32_OVF, JIT_DoubleToUInt32Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt64, JIT_DoubleToUInt64, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DoubleToUInt64_OVF, JIT_DoubleToUInt64Ovf, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_FLTREM, JIT_FltRem, CORINFO_HELP_SIG_8_STACK)
JITHELPER(CORINFO_HELP_DBLREM, JIT_DblRem, CORINFO_HELP_SIG_16_STACK)
JITHELPER(CORINFO_HELP_FLTROUND, JIT_FloatRound, CORINFO_HELP_SIG_8_STACK)
Expand Down
28 changes: 18 additions & 10 deletions src/coreclr/inc/readytorun.h
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Original file line number Diff line number Diff line change
Expand Up @@ -347,8 +347,8 @@ enum ReadyToRunHelper
READYTORUN_HELPER_LLsh = 0xC7,
READYTORUN_HELPER_LRsh = 0xC8,
READYTORUN_HELPER_LRsz = 0xC9,
READYTORUN_HELPER_Lng2Dbl = 0xCA,
READYTORUN_HELPER_ULng2Dbl = 0xCB,
READYTORUN_HELPER_Int64ToDouble = 0xCA,
READYTORUN_HELPER_UInt64ToDouble = 0xCB,

// 32-bit division helpers
READYTORUN_HELPER_Div = 0xCC,
Expand All @@ -357,14 +357,22 @@ enum ReadyToRunHelper
READYTORUN_HELPER_UMod = 0xCF,

// Floating point conversions
READYTORUN_HELPER_Dbl2Int = 0xD0,
READYTORUN_HELPER_Dbl2IntOvf = 0xD1,
READYTORUN_HELPER_Dbl2Lng = 0xD2,
READYTORUN_HELPER_Dbl2LngOvf = 0xD3,
READYTORUN_HELPER_Dbl2UInt = 0xD4,
READYTORUN_HELPER_Dbl2UIntOvf = 0xD5,
READYTORUN_HELPER_Dbl2ULng = 0xD6,
READYTORUN_HELPER_Dbl2ULngOvf = 0xD7,
READYTORUN_HELPER_DoubleToInt32 = 0xD0,
READYTORUN_HELPER_DoubleToInt32Ovf = 0xD1,
READYTORUN_HELPER_DoubleToInt64 = 0xD2,
READYTORUN_HELPER_DoubleToInt64Ovf = 0xD3,
READYTORUN_HELPER_DoubleToUInt32 = 0xD4,
READYTORUN_HELPER_DoubleToUInt32Ovf = 0xD5,
READYTORUN_HELPER_DoubleToUInt64 = 0xD6,
READYTORUN_HELPER_DoubleToUInt64Ovf = 0xD7,
READYTORUN_HELPER_DoubleToInt8 = 0xD8,
READYTORUN_HELPER_DoubleToInt8Ovf = 0xD9,
READYTORUN_HELPER_DoubleToInt16 = 0xDA,
READYTORUN_HELPER_DoubleToInt16Ovf = 0xDB,
READYTORUN_HELPER_DoubleToUInt8 = 0xDC,
READYTORUN_HELPER_DoubleToUInt8Ovf = 0xDD,
READYTORUN_HELPER_DoubleToUInt16 = 0xDE,
READYTORUN_HELPER_DoubleToUInt16Ovf = 0xDF,

// Floating point ops
READYTORUN_HELPER_DblRem = 0xE0,
Expand Down
28 changes: 18 additions & 10 deletions src/coreclr/inc/readytorunhelpers.h
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Expand Up @@ -66,22 +66,30 @@ HELPER(READYTORUN_HELPER_ULMod, CORINFO_HELP_ULMOD,
HELPER(READYTORUN_HELPER_LLsh, CORINFO_HELP_LLSH, )
HELPER(READYTORUN_HELPER_LRsh, CORINFO_HELP_LRSH, )
HELPER(READYTORUN_HELPER_LRsz, CORINFO_HELP_LRSZ, )
HELPER(READYTORUN_HELPER_Lng2Dbl, CORINFO_HELP_LNG2DBL, )
HELPER(READYTORUN_HELPER_ULng2Dbl, CORINFO_HELP_ULNG2DBL, )
HELPER(READYTORUN_HELPER_Int64ToDouble, CORINFO_HELP_Int64ToDouble, )
HELPER(READYTORUN_HELPER_UInt64ToDouble, CORINFO_HELP_UInt64ToDouble, )

HELPER(READYTORUN_HELPER_Div, CORINFO_HELP_DIV, )
HELPER(READYTORUN_HELPER_Mod, CORINFO_HELP_MOD, )
HELPER(READYTORUN_HELPER_UDiv, CORINFO_HELP_UDIV, )
HELPER(READYTORUN_HELPER_UMod, CORINFO_HELP_UMOD, )

HELPER(READYTORUN_HELPER_Dbl2Int, CORINFO_HELP_DBL2INT, )
HELPER(READYTORUN_HELPER_Dbl2IntOvf, CORINFO_HELP_DBL2INT_OVF, )
HELPER(READYTORUN_HELPER_Dbl2Lng, CORINFO_HELP_DBL2LNG, )
HELPER(READYTORUN_HELPER_Dbl2LngOvf, CORINFO_HELP_DBL2LNG_OVF, )
HELPER(READYTORUN_HELPER_Dbl2UInt, CORINFO_HELP_DBL2UINT, )
HELPER(READYTORUN_HELPER_Dbl2UIntOvf, CORINFO_HELP_DBL2UINT_OVF, )
HELPER(READYTORUN_HELPER_Dbl2ULng, CORINFO_HELP_DBL2ULNG, )
HELPER(READYTORUN_HELPER_Dbl2ULngOvf, CORINFO_HELP_DBL2ULNG_OVF, )
HELPER(READYTORUN_HELPER_DoubleToInt32, CORINFO_HELP_DoubleToInt32, )
HELPER(READYTORUN_HELPER_DoubleToInt32Ovf, CORINFO_HELP_DoubleToInt32_OVF, )
HELPER(READYTORUN_HELPER_DoubleToInt64, CORINFO_HELP_DoubleToInt64, )
HELPER(READYTORUN_HELPER_DoubleToInt64Ovf, CORINFO_HELP_DoubleToInt64_OVF, )
HELPER(READYTORUN_HELPER_DoubleToUInt32, CORINFO_HELP_DoubleToUInt32, )
HELPER(READYTORUN_HELPER_DoubleToUInt32Ovf, CORINFO_HELP_DoubleToUInt32_OVF, )
HELPER(READYTORUN_HELPER_DoubleToUInt64, CORINFO_HELP_DoubleToUInt64, )
HELPER(READYTORUN_HELPER_DoubleToUInt64Ovf, CORINFO_HELP_DoubleToUInt64_OVF, )
HELPER(READYTORUN_HELPER_DoubleToInt8, CORINFO_HELP_DoubleToInt8, )
HELPER(READYTORUN_HELPER_DoubleToInt8Ovf, CORINFO_HELP_DoubleToInt8_OVF, )
HELPER(READYTORUN_HELPER_DoubleToInt16, CORINFO_HELP_DoubleToInt16, )
HELPER(READYTORUN_HELPER_DoubleToInt16Ovf, CORINFO_HELP_DoubleToInt16_OVF, )
HELPER(READYTORUN_HELPER_DoubleToUInt8, CORINFO_HELP_DoubleToUInt8, )
HELPER(READYTORUN_HELPER_DoubleToUInt8Ovf, CORINFO_HELP_DoubleToUInt8_OVF, )
HELPER(READYTORUN_HELPER_DoubleToUInt16, CORINFO_HELP_DoubleToUInt16, )
HELPER(READYTORUN_HELPER_DoubleToUInt16Ovf, CORINFO_HELP_DoubleToUInt16_OVF, )

HELPER(READYTORUN_HELPER_FltRem, CORINFO_HELP_FLTREM, )
HELPER(READYTORUN_HELPER_DblRem, CORINFO_HELP_DBLREM, )
Expand Down
96 changes: 42 additions & 54 deletions src/coreclr/jit/codegenxarch.cpp
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Expand Up @@ -7167,11 +7167,6 @@ void CodeGen::genIntToFloatCast(GenTree* treeNode)
var_types srcType = op1->TypeGet();
assert(!varTypeIsFloating(srcType) && varTypeIsFloating(dstType));

#if !defined(TARGET_64BIT)
// We expect morph to replace long to float/double casts with helper calls
noway_assert(!varTypeIsLong(srcType));
#endif // !defined(TARGET_64BIT)

// Since xarch emitter doesn't handle reporting gc-info correctly while casting away gc-ness we
// ensure srcType of a cast is non gc-type. Codegen should never see BYREF as source type except
// for GT_LCL_VAR_ADDR and GT_LCL_FLD_ADDR that represent stack addresses and can be considered
Expand Down Expand Up @@ -7200,10 +7195,18 @@ void CodeGen::genIntToFloatCast(GenTree* treeNode)
emitAttr srcSize = EA_ATTR(genTypeSize(srcType));
noway_assert((srcSize == EA_ATTR(genTypeSize(TYP_INT))) || (srcSize == EA_ATTR(genTypeSize(TYP_LONG))));

// Also we don't expect to see uint32 -> float/double and uint64 -> float conversions
// here since they should have been lowered appropriately.
#if defined(TARGET_X86)
// x86 doesn't expect to see int64/uint32/uint64 -> float/double here since they should have been
// replaced with helper calls by the front end.
noway_assert(!varTypeIsLong(srcType));
noway_assert(srcType != TYP_UINT);
noway_assert((srcType != TYP_ULONG) || (dstType != TYP_FLOAT));
#endif // TARGET_X86

#if defined(TARGET_AMD64)
// x64 shouldn't see a uint64 -> float/double as it should have been lowered to an alternative
// sequence -or- converted to a helper call by the front end.
noway_assert(srcType != TYP_ULONG);
#endif // TARGET_AMD64

// To convert int to a float/double, cvtsi2ss/sd SSE2 instruction is used
// which does a partial write to lower 4/8 bytes of xmm register keeping the other
Expand All @@ -7219,46 +7222,27 @@ void CodeGen::genIntToFloatCast(GenTree* treeNode)

// Note that here we need to specify srcType that will determine
// the size of source reg/mem operand and rex.w prefix.
instruction ins = ins_FloatConv(dstType, TYP_INT, emitTypeSize(srcType));
GetEmitter()->emitInsBinary(ins, emitTypeSize(srcType), treeNode, op1);

// Handle the case of srcType = TYP_ULONG. SSE2 conversion instruction
// will interpret ULONG value as LONG. Hence we need to adjust the
// result if sign-bit of srcType is set.
if (srcType == TYP_ULONG)
{
// The instruction sequence below is less accurate than what clang
// and gcc generate. However, we keep the current sequence for backward compatibility.
// If we change the instructions below, FloatingPointUtils::convertUInt64ToDobule
// should be also updated for consistent conversion result.
assert(dstType == TYP_DOUBLE);
assert(op1->isUsedFromReg());
var_types fromType = srcType;

// Set the flags without modifying op1.
// test op1Reg, op1Reg
inst_RV_RV(INS_test, op1->GetRegNum(), op1->GetRegNum(), srcType);
#if defined(TARGET_AMD64)
if (fromType == TYP_UINT)
{
// There isn't an instruction that directly allows conversion from TYP_UINT
// so we convert from TYP_LONG instead.

// No need to adjust result if op1 >= 0 i.e. positive
// Jge label
BasicBlock* label = genCreateTempLabel();
inst_JMP(EJ_jge, label);
fromType = TYP_LONG;

// Adjust the result
// result = result + 0x43f00000 00000000
// addsd resultReg, 0x43f00000 00000000
CORINFO_FIELD_HANDLE* cns = &u8ToDblBitmask;
if (*cns == nullptr)
{
double d;
static_assert_no_msg(sizeof(double) == sizeof(__int64));
*((__int64*)&d) = 0x43f0000000000000LL;
// We require the value to come from a register so the upper bits here
// will be zero and we can know we'll get a correct result.
assert(op1->isUsedFromReg());
}
#endif // TARGET_AMD64

*cns = GetEmitter()->emitFltOrDblConst(d, EA_8BYTE);
}
GetEmitter()->emitIns_R_C(INS_addsd, EA_8BYTE, treeNode->GetRegNum(), *cns, 0);
assert(!varTypeIsUnsigned(fromType));

genDefineTempLabel(label);
}
emitAttr attr = emitTypeSize(fromType);
instruction ins = ins_FloatConv(dstType, fromType, attr);
GetEmitter()->emitInsBinary(ins, attr, treeNode, op1);

genProduceReg(treeNode);
}
Expand All @@ -7277,8 +7261,6 @@ void CodeGen::genIntToFloatCast(GenTree* treeNode)
// The treeNode must have an assigned register.
// SrcType=float/double and DstType= int32/uint32/int64/uint64
//
// TODO-XArch-CQ: (Low-pri) - generate in-line code when DstType = uint64
//
void CodeGen::genFloatToIntCast(GenTree* treeNode)
{
// we don't expect to see overflow detecting float/double --> int type conversions here
Expand All @@ -7297,9 +7279,9 @@ void CodeGen::genFloatToIntCast(GenTree* treeNode)
}
#endif

var_types srcType = treeNode->CastFromType();
var_types dstType = treeNode->CastToType();
var_types srcType = op1->TypeGet();
assert(varTypeIsFloating(srcType) && !varTypeIsFloating(dstType));
assert(varTypeIsFloating(srcType) && varTypeIsIntegral(dstType));

// We should never be seeing dstType whose size is neither sizeof(TYP_INT) nor sizeof(TYP_LONG).
// For conversions to byte/sbyte/int16/uint16 from float/double, we would expect the
Expand All @@ -7309,17 +7291,23 @@ void CodeGen::genFloatToIntCast(GenTree* treeNode)
emitAttr dstSize = EA_ATTR(genTypeSize(dstType));
noway_assert((dstSize == EA_ATTR(genTypeSize(TYP_INT))) || (dstSize == EA_ATTR(genTypeSize(TYP_LONG))));

// We shouldn't be seeing uint64 here as it should have been converted
// into a helper call by either front-end or lowering phase.
noway_assert(!varTypeIsUnsigned(dstType) || (dstSize != EA_ATTR(genTypeSize(TYP_LONG))));
#if defined(TARGET_X86)
// x86 shouldn't see casts to int64/uint32/uint64 as they should have been convered into
// helper calls by the front-end.

noway_assert(dstType != TYP_UINT);
noway_assert(!varTypeIsLong(dstType));
#else
// x64 shouldn't see casts to uint64 as they should have been lowered into an alternative sequence
noway_assert(dstType != TYP_ULONG);

// If the dstType is TYP_UINT, we have 32-bits to encode the
// float number. Any of 33rd or above bits can be the sign bit.
// To achieve it we pretend as if we are converting it to a long.
if (varTypeIsUnsigned(dstType) && (dstSize == EA_ATTR(genTypeSize(TYP_INT))))
// If the dstType is TYP_UINT, we can convert to TYP_LONG and implicitly take
// the lower 32-bits as the result.
if ((dstType == TYP_UINT) && (dstSize == EA_ATTR(genTypeSize(TYP_INT))))
{
dstType = TYP_LONG;
}
#endif // TARGET_X86

// Note that we need to specify dstType here so that it will determine
// the size of destination integer register and also the rex.w prefix.
Expand Down
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