FJCVTZS

Floating-point Javascript Convert to Signed fixed-point, rounding toward Zero. This instruction converts the double-precision floating-point value in the SIMD&FP source register to a 32-bit signed integer using the Round towards Zero rounding mode, and writes the result to the general-purpose destination register. If the result is too large to be represented as a signed 32-bit integer, then the result is the integer modulo 2³², as held in a 32-bit signed integer.

This instruction can generate a floating-point exception. Depending on the settings in FPCR, the exception results in either a flag being set in FPSR or a synchronous exception being generated. For more information, see Floating-point exception traps.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

Double-precision to 32-bit
(FEAT_JSCVT)

integer d = UInt(Rd); integer n = UInt(Rn); integer intsize = if sf == '1' then 64 else 32; integer fltsize; FPConvOp op; FPRounding rounding; boolean unsigned; integer part; case ftype of when '00' fltsize = 32; when '01' fltsize = 64; when '10' if opcode<2:1>:rmode != '11 01' then UNDEFINED; fltsize = 128; when '11' if HaveFP16Ext() then fltsize = 16; else UNDEFINED; case opcode<2:1>:rmode of when '00 xx' // FCVT[NPMZ][US] rounding = FPDecodeRounding(rmode); unsigned = (opcode<0> == '1'); op = FPConvOp_CVT_FtoI; when '01 00' // [US]CVTF rounding = FPRoundingMode(FPCR[]); unsigned = (opcode<0> == '1'); op = FPConvOp_CVT_ItoF; when '10 00' // FCVTA[US] rounding = FPRounding_TIEAWAY; unsigned = (opcode<0> == '1'); op = FPConvOp_CVT_FtoI; when '11 00' // FMOV if fltsize != 16 && fltsize != intsize then UNDEFINED; op = if opcode<0> == '1' then FPConvOp_MOV_ItoF else FPConvOp_MOV_FtoI; part = 0; when '11 01' // FMOV D[1] if intsize != 64 || fltsize != 128 then UNDEFINED; op = if opcode<0> == '1' then FPConvOp_MOV_ItoF else FPConvOp_MOV_FtoI; part = 1; fltsize = 64; // size of D[1] is 64 when '11 11' // FJCVTZS if !HaveFJCVTZSExt() then UNDEFINED; rounding = FPRounding_ZERO; unsigned = (opcode<0> == '1'); op = FPConvOp_CVT_FtoI_JS; otherwise UNDEFINED;