Table 4 Options for +FP[flags]
Flag | Description |
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|
V (v) | Trap on invalid |
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Z (z) | Trap on divide by zero. |
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O (o) | Trap on |
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|
U (u) | Trap on |
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|
I (i) | Trap on |
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|
D (d) | Enable sudden underflow (flush to zero) of denormalized values. |
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|
To dynamically change these settings at runtime, see fesetenv(3M).
+FPmode
+FPmode specifies how the
To dynamically change these settings at run time, refer to fenv(5), fesettrapenable(3M), and fesetround(3M).
+O[no]libmerrno
+O[no]libmerrno
Description:
The +O[no]libmerrno option enables [disables] support for errno in libm functions. The default is +Onolibmerrno for C++, c99, or
In
+Oprefetch_latency
+Oprefetch_latency=cycles
The +Oprefetch_latency option applies to loops for which the compiler generates data prefetch instructions. cycles represents the number of cycles for a data cache miss. For a given loop, the compiler divides cycles by the estimated loop length to arrive at the number of loop iterations for which to generate advanced prefetches.
cycles must be in the range of 0 to 10000. A value of 0 instructs the compiler to use the default value, which is 480 cycles for loops containing
For tuning purposes, it is recommended that users measure their application’s performance using a few different prefetch latency settings to determine the optimal value. Some
+O[no]preserved_fpregs
+O[no]preserved_fpregs
The +O[no]preserved_fprefs option specifies whether the compiler is allowed [not allowed] to make use of the preserved subset of the
The default is +Opreserved_fpregs.
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