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FMAXNM (scalar)

Floating-point Maximum Number (scalar). This instruction compares the first and second source SIMD&FP register values, and writes the larger of the two floating-point values to the destination SIMD&FP register.

NaNs are handled according to the IEEE 754-2008 standard. If one vector element is numeric and the other is a quiet NaN, the result that is placed in the vector is the numerical value, otherwise the result is identical to FMAX (scalar).

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.

313029282726252423222120191817161514131211109876543210
00011110ftype1Rm011010RnRd
op

Half-precision (ftype == 11)
(Armv8.2)

FMAXNM <Hd>, <Hn>, <Hm>

Single-precision (ftype == 00)

FMAXNM <Sd>, <Sn>, <Sm>

Double-precision (ftype == 01)

FMAXNM <Dd>, <Dn>, <Dm>

integer d = UInt(Rd);
integer n = UInt(Rn);
integer m = UInt(Rm);

integer datasize;
case ftype of
    when '00' datasize = 32;
    when '01' datasize = 64;
    when '10' UNDEFINED;
    when '11'
        if HaveFP16Ext() then
            datasize = 16;
        else
            UNDEFINED;

Assembler Symbols

<Dd>

Is the 64-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Dn>

Is the 64-bit name of the first SIMD&FP source register, encoded in the "Rn" field.

<Dm>

Is the 64-bit name of the second SIMD&FP source register, encoded in the "Rm" field.

<Hd>

Is the 16-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Hn>

Is the 16-bit name of the first SIMD&FP source register, encoded in the "Rn" field.

<Hm>

Is the 16-bit name of the second SIMD&FP source register, encoded in the "Rm" field.

<Sd>

Is the 32-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Sn>

Is the 32-bit name of the first SIMD&FP source register, encoded in the "Rn" field.

<Sm>

Is the 32-bit name of the second SIMD&FP source register, encoded in the "Rm" field.

Operation

CheckFPAdvSIMDEnabled64();
bits(datasize) result;
bits(datasize) operand1 = V[n];
bits(datasize) operand2 = V[m];

result = FPMaxNum(operand1, operand2, FPCR[]);
V[d] = result;