Implement fenv rouding and exceptions for soft-fp, as per SuperH
arch specification.
No new tests required, as it's already covered by many torture tests
with fenv_exceptions.
PR target/118257
libgcc/ChangeLog:
* config/sh/sfp-machine.h (_FPU_GETCW): Implement with builtin.
(_FPU_SETCW): Likewise.
(FP_EX_ENABLE_SHIFT): Derive from arch spec.
(FP_EX_CAUSE_SHIFT): Likewise.
(FP_RND_MASK): Likewise.
(FP_EX_INVALID): Likewise.
(FP_EX_DIVZERO): Likewise.
(FP_EX_ALL): Likewise.
(FP_EX_OVERFLOW): Likewise.
(FP_EX_UNDERFLOW): Likewise.
(FP_EX_INEXACT): Likewise.
(_FP_DECL_EX): Declear default FCSR value.
(FP_RND_NEAREST): Derive from arch spec.
(FP_RND_ZERO): Likewise.
(FP_INIT_ROUNDMODE): Likewise.
(FP_ROUNDMODE): Likewise.
(FP_TRAPPING_EXCEPTIONS): Likewise.
(FP_HANDLE_EXCEPTIONS): Implement with _FPU_SETCW.
Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
Changes in v2:
- Use builtins tp implement _FPU_GETCW/_FPU_SETCW.
- Link to v1:
https://inbox.sourceware.org/20250101-sh4-fenv-exception-v1-1-9bafef83a...@flygoat.com
---
libgcc/config/sh/sfp-machine.h | 46 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
diff --git a/libgcc/config/sh/sfp-machine.h b/libgcc/config/sh/sfp-machine.h
index
68695cc30f941f0738016da4f7d825808b57d24b..1f36bbc653a884b3a644a0f97e26c030652c151b
100644
--- a/libgcc/config/sh/sfp-machine.h
+++ b/libgcc/config/sh/sfp-machine.h
@@ -76,6 +76,52 @@ typedef int __gcc_CMPtype __attribute__ ((mode
(__libgcc_cmp_return__)));
R##_c = FP_CLS_NAN; \
} while (0)
+#ifdef __SH_FPU_ANY__
+#define _FPU_GETCW(fpscr) fpscr = __builtin_sh_get_fpscr ()
+#define _FPU_SETCW(fpscr) __builtin_sh_set_fpscr (fpscr)
+#define FP_EX_ENABLE_SHIFT 5
+#define FP_EX_CAUSE_SHIFT 10
+
+#define FP_EX_INVALID 0x0040
+#define FP_EX_DIVZERO 0x0020
+#if defined (__SH2E__)
+#define FP_EX_ALL (FP_EX_DIVZERO | FP_EX_INVALID)
+#else
+#define FP_EX_OVERFLOW 0x0010
+#define FP_EX_UNDERFLOW 0x0008
+#define FP_EX_INEXACT 0x0004
+#define FP_EX_ALL (FP_EX_DIVZERO | FP_EX_INEXACT | \
+ FP_EX_INVALID | FP_EX_OVERFLOW | FP_EX_UNDERFLOW)
+#endif
+#define _FP_DECL_EX \
+ unsigned int _fcsr __attribute__ ((unused)) = FP_RND_NEAREST
+/* Rounding modes. */
+#define FP_RND_NEAREST 0x0
+#define FP_RND_ZERO 0x1
+/* Placeholder, hardware does not have PINF/MINF modes. */
+#define FP_RND_PINF 0x2
+#define FP_RND_MINF 0x3
+#define FP_RND_MASK 3
+
+#define FP_INIT_ROUNDMODE _FPU_GETCW (_fcsr)
+#define FP_ROUNDMODE (_fcsr & FP_RND_MASK)
+#define FP_TRAPPING_EXCEPTIONS ((_fcsr >> FP_EX_ENABLE_SHIFT) & FP_EX_ALL)
+#define FP_HANDLE_EXCEPTIONS \
+ do { \
+ _fcsr &= ~(FP_EX_ALL << FP_EX_CAUSE_SHIFT); \
+ _fcsr |= _fex | (_fex << FP_EX_CAUSE_SHIFT); \
+ _FPU_SETCW (_fcsr); \
+ } while (0)
+#else
+#define FP_EX_INVALID (1 << 4)
+#define FP_EX_DIVZERO (1 << 3)
+#if !defined (__SH2E__)
+#define FP_EX_OVERFLOW (1 << 2)
+#define FP_EX_UNDERFLOW (1 << 1)
+#define FP_EX_INEXACT (1 << 0)
+#endif
+#endif
+
#define _FP_TININESS_AFTER_ROUNDING 1
#define __LITTLE_ENDIAN 1234
---
base-commit: 48ab66eed5843ea542a77bf882b732afa187fa8b
change-id: 20250101-sh4-fenv-exception-a3d2197f0bc9
prerequisite-change-id: 20241231-sh-nan-b777b3af0342:v3
Best regards,
--
Jiaxun Yang <jiaxun.y...@flygoat.com>
