mirror of
https://github.com/crosstool-ng/crosstool-ng.git
synced 2024-12-25 07:21:05 +00:00
72e07cce8f
Bring in upstream support for newer float standards being used by GCC. Fixes #1957 Signed-off-by: Chris Packham <judge.packham@gmail.com>
51 lines
2.0 KiB
Diff
51 lines
2.0 KiB
Diff
From 91f99d323b39dc0c06c40038791db9861d4b76b9 Mon Sep 17 00:00:00 2001
|
|
From: Kito Cheng <kito.cheng@sifive.com>
|
|
Date: Mon, 12 Jul 2021 17:17:21 +0800
|
|
Subject: [PATCH] Minimal support for ISO/IEC TS 18661-3.
|
|
|
|
- GCC will set __FLT_EVAL_METHOD__ to 16 if __fp16 supported, e.g.
|
|
cortex-a55/aarch64.
|
|
- $ aarch64-unknown-elf-gcc -v 2>&1 |grep version
|
|
gcc version 9.2.0 (GCC)
|
|
- $ aarch64-unknown-elf-gcc -E -dM -mcpu=cortex-a55 - < /dev/null |grep FLT_EVAL_METHOD
|
|
#define __FLT_EVAL_METHOD__ 16
|
|
#define __FLT_EVAL_METHOD_TS_18661_3__ 16
|
|
#define __FLT_EVAL_METHOD_C99__ 16
|
|
- The behavior of __FLT_EVAL_METHOD__ == 16 is same as
|
|
__FLT_EVAL_METHOD__ == 0 except for float16_t, but newlib didn't
|
|
support float16_t.
|
|
|
|
ISO/IEC TS 18661-3:
|
|
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2405.pdf
|
|
|
|
V2 Changes:
|
|
- List Howland, Craig D as co-author since he provide the draft of comment
|
|
in math.h.
|
|
|
|
Co-authored-by: "Howland, Craig D" <howland@LGSInnovations.com>
|
|
---
|
|
newlib/libc/include/math.h | 12 +++++++++++-
|
|
1 file changed, 11 insertions(+), 1 deletion(-)
|
|
|
|
--- a/newlib/libc/include/math.h
|
|
+++ b/newlib/libc/include/math.h
|
|
@@ -146,7 +146,17 @@
|
|
#define __TMP_FLT_EVAL_METHOD
|
|
#endif /* FLT_EVAL_METHOD */
|
|
#if defined FLT_EVAL_METHOD
|
|
- #if FLT_EVAL_METHOD == 0
|
|
+/* FLT_EVAL_METHOD == 16 has meaning as defined in ISO/IEC TS 18661-3,
|
|
+ * which provides non-compliant extensions to C and POSIX (by adding
|
|
+ * additional positive values for FLT_EVAL_METHOD). It effectively has
|
|
+ * same meaning as the C99 and C11 definitions for value 0, while also
|
|
+ * serving as a flag that the _Float16 (float16_t) type exists.
|
|
+ *
|
|
+ * FLT_EVAL_METHOD could be any number of bits of supported floating point
|
|
+ * format (e.g. 32, 64, 128), but currently only AArch64 and few other targets
|
|
+ * might define that as 16. */
|
|
+ #if (FLT_EVAL_METHOD == 0) \
|
|
+ || (FLT_EVAL_METHOD == 16)
|
|
typedef float float_t;
|
|
typedef double double_t;
|
|
#elif FLT_EVAL_METHOD == 1
|