# fmax, fmaxf, fmaxl

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< c‎ | numeric‎ | math

Defined in header ``<math.h>`` |  |
float fmaxf( float x, float y ); | (1) | (since C99)
double fmax( double x, double y ); | (2) | (since C99)
long double fmaxl( long double x, long double y ); | (3) | (since C99)
Defined in header ``<tgmath.h>`` |  |
#define fmax( x, y ) | (4) | (since C99)

1-3) Returns the larger of two floating-point arguments, treating NaNs as missing data (between a NaN and a numeric value, the numeric value is chosen).
4) Type-generic macro: If any argument has type long double, `fmaxl` is called. Otherwise, if any argument has integer type or has type double, `fmax` is called. Otherwise, `fmaxf` is called.

### Parameters

x, y | - | floating-point values

### Return value

If successful, returns the larger of two floating-point values. The value returned is exact and does not depend on any rounding modes.

### Error handling

This function is not subject to any of the error conditions specified in `math_errhandling`.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

- If one of the two arguments is NaN, the value of the other argument is returned.
- Only if both arguments are NaN is NaN returned.

### Notes

This function is not required to be sensitive to the sign of zero, although some implementations additionally enforce that if one argument is +0 and the other is -0, then +0 is returned.

### Example

Run this code

    #include <math.h>
    #include <stdio.h>

    int main(void)
    {
        printf("fmax(2,1)    = %f\n", fmax(2,1));
        printf("fmax(-Inf,0) = %f\n", fmax(-INFINITY,0));
        printf("fmax(NaN,-1) = %f\n", fmax(NAN,-1));
    }

Output:

    fmax(2,1)    = 2.000000
    fmax(-Inf,0) = 0.000000
    fmax(NaN,-1) = -1.000000

### References

- C23 standard (ISO/IEC 9899:2024):

  - 7.12.12.2 The fmax functions (p: TBD)

  - 7.25 Type-generic math <tgmath.h> (p: TBD)

  - F.10.9.2 The fmax functions (p: TBD)

- C17 standard (ISO/IEC 9899:2018):

  - 7.12.12.2 The fmax functions (p: 188)

  - 7.25 Type-generic math <tgmath.h> (p: 397)

  - F.10.9.2 The fmax functions (p: 386)

- C11 standard (ISO/IEC 9899:2011):

  - 7.12.12.2 The fmax functions (p: 257-258)

  - 7.25 Type-generic math <tgmath.h> (p: 373-375)

  - F.10.9.2 The fmax functions (p: 530)

- C99 standard (ISO/IEC 9899:1999):

  - 7.12.12.2 The fmax functions (p: 238-239)

  - 7.22 Type-generic math <tgmath.h> (p: 335-337)

  - F.9.9.2 The fmax functions (p: 466)

### See also

isgreater (C99) | checks if the first floating-point argument is greater than the second (function macro)
fminfminffminl (C99)(C99)(C99) | determines smaller of two floating-point values (function)
C++ documentation for fmax

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