On Mon, 28 May 2012, Matthew Gretton-Dann wrote: > This patch adds a variety of predefined macros to reveal the presence of > various features of the ARM architecture. These are detailed in the ARM > C Language Extensions specification, available here: > http://infocenter.arm.com/help/topic/com.arm.doc.ihi0053-/index.html
Are there any plans to implement the change in __fp16 semantics in this document (single rounding for conversion from double to __fp16, whereas the specification previously implemented was double rounding)? And, more generally, the various features in the document not currently implemented in GCC or implemented differently from the specification? > __ARM_FEATURE_FMA which is defined when the fused multiply-accumulate > instructions are available for floating-point and/or Advanced SIMD > values. Note that the ARM port is currently lacking the fma instruction patterns to implement the __builtin_fma* built-in functions for processors with those instructions. Support for those would be a straightforward and useful addition to GCC. Is there a reason the ACLE doesn't include a predefined macro to say whether registers d16-d31 are known at compile time to be available? That would occasionally be useful (see my comments in <http://sourceware.org/ml/libc-ports/2012-04/msg00087.html>, for example). -- Joseph S. Myers jos...@codesourcery.com
