fpMacros(3) Manual Page

The FP_CONTRACT pragma can be used to allow (if the state is on) or disallow (if the state is off) the implementation to contract expressions. Each pragma can occur either outside external declarations or preceding all explicit declarations and statements inside a compound statement. When outside external declarations, the pragma takes effect from its occurrence until another FP_CONTRACT pragma is encountered, or until the end of the translation unit. When inside a compound statement, the pragma takes effect from its occurrence until another FP_CONTRACT pragma is encountered (including within a nested compound statement), or until the end of the compound statement; at the end of a compound statement the state for the pragma is restored to its condition just before the compound statement. If this pragma is used in any other context, the behavior is undefined.

The pragma definition to set FP_CONTRACT is:

The FP_FAST_FMAF macro indicates whether the fma function is fast compared with direct code for single precision floating-point. If defined, the FP_FAST_FMAF macro shall indicate that the fma function generally executes about as fast as, or faster than, a multiply and an add of float operands.

The macro names given in the following list must use the values specified. These constant expressions are suitable for use in #if preprocessing directives.

The following table describes the built-in macro names given above in the OpenCL C programming language and the corresponding macro names available to the application.

The following macros shall expand to integer constant expressions whose values are returned by ilogb(x) if x is zero or NaN, respectively. The value of FP_ILOGB0 shall be either INT_MIN or -INT_MAX. The value of FP_ILOGBNAN shall be either INT_MAX or INT_MIN.

The following constants are also available. They are of type float and are accurate within the precision of the float type.

If double-precision is supported by the device, then the following macros and constants are also available:

The FP_FAST_FMA macro indicates whether the fma() family of functions are fast compared with direct code for double-precision floating-point. If defined, the FP_FAST_FMA macro shall indicate that the fma() function generally executes about as fast as, or faster than, a multiply and an add of double operands

The macro names given in the following list must use the values specified. These constant expressions are suitable for use in #if preprocessing directives.

The following table describes the built-in macro names given above in the OpenCL C programming language and the corresponding macro names available to the application.

The following constants are also available. They are of type double and are accurate within the precision of the double type.

If the cl_khr_fp16 extension macro is supported, then the following macros and constants are also available:

The FP_FAST_FMA_HALF macro indicates whether the fma() family of functions are fast compared with direct code for half-precision floating-point. If defined, the FP_FAST_FMA_HALF macro shall indicate that the fma() function generally executes about as fast as, or faster than, a multiply and an add of half operands.

The macro names given in the following list must use the values specified. These constant expressions are suitable for use in #if preprocessing directives.

The following table describes the built-in macro names given above in the OpenCL C programming language and the corresponding macro names available to the application.

The following constants are also available. They are of type half and are accurate within the precision of the half type.

integerMacros

For more information, see the OpenCL C Specification

This page is extracted from the OpenCL C Specification. Fixes and changes should be made to the Specification, not directly.

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