[v5,12/17] RISC-V: Fix llrint and llround missing exceptions on RV32

Message ID 9a6481b56407222bdfd75ead53b2429871a295ad.1597851293.git.alistair.francis@wdc.com
State Committed
Headers
Series glibc port for 32-bit RISC-V (RV32) |

Commit Message

Alistair Francis Aug. 19, 2020, 3:39 p.m. UTC
  From: Zong Li <zongbox@gmail.com>

Conversions from a float to a long long on 32-bit RISC-V (RV32) may not
raise the correct exceptions on overflow, it also may raise spurious
"inexact" exceptions on non overflow cases.  This patch fixes the
problem, similarly to the fix for MIPS, ARM and S390.
---
 .../riscv/rv32/fix-fp-int-convert-overflow.h  | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 sysdeps/riscv/rv32/fix-fp-int-convert-overflow.h
  

Comments

Maciej W. Rozycki Aug. 21, 2020, 11:36 a.m. UTC | #1
On Wed, 19 Aug 2020, Alistair Francis via Libc-alpha wrote:

> From: Zong Li <zongbox@gmail.com>
> 
> Conversions from a float to a long long on 32-bit RISC-V (RV32) may not
> raise the correct exceptions on overflow, it also may raise spurious
> "inexact" exceptions on non overflow cases.  This patch fixes the
> problem, similarly to the fix for MIPS, ARM and S390.

 LGTM.

Reviewed-by: Maciej W. Rozycki <macro@wdc.com>

  Maciej
  

Patch

diff --git a/sysdeps/riscv/rv32/fix-fp-int-convert-overflow.h b/sysdeps/riscv/rv32/fix-fp-int-convert-overflow.h
new file mode 100644
index 0000000000..ddf9e3c351
--- /dev/null
+++ b/sysdeps/riscv/rv32/fix-fp-int-convert-overflow.h
@@ -0,0 +1,38 @@ 
+/* Fix for conversion of floating point to integer overflow.  RISC-V version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef FIX_FP_INT_CONVERT_OVERFLOW_H
+#define FIX_FP_INT_CONVERT_OVERFLOW_H	1
+
+/* The generic libgcc2.c conversions from floating point to long long
+   may not raise the correct exceptions on overflow (and may raise
+   spurious "inexact" exceptions even in non-overflow cases, see
+   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>).  */
+#define FIX_FLT_LONG_CONVERT_OVERFLOW 0
+#define FIX_FLT_LLONG_CONVERT_OVERFLOW 1
+
+#define FIX_DBL_LONG_CONVERT_OVERFLOW 0
+#define FIX_DBL_LLONG_CONVERT_OVERFLOW 1
+
+#define FIX_LDBL_LONG_CONVERT_OVERFLOW 0
+#define FIX_LDBL_LLONG_CONVERT_OVERFLOW 0
+
+#define FIX_FLT128_LONG_CONVERT_OVERFLOW 0
+#define FIX_FLT128_LLONG_CONVERT_OVERFLOW 0
+
+#endif /* fix-fp-int-convert-overflow.h */