svn commit: r362788 - head/lib/libc/riscv

[Mitchell Horne]

Author: mhorne
Date: Mon Jun 29 19:30:35 2020
New Revision: 362788
URL: https://svnweb.freebsd.org/changeset/base/362788

Log:
  Fix printf(3) output of long doubles on RISC-V
  
  When the RISC-V port was initially committed to FreeBSD, GCC would
  generate 64-bit long doubles, and the definitions in _fpmath.h reflected
  that. This was changed to 128-bit in GCC later that year [1], but the
  definitions were never updated, despite the documented workaround. This
  causes printf(3) and friends to interpret only the low 64-bits of a long
  double in ldtoa, thereby printing incorrect values.
  
  Update the definitions now that both clang and GCC generate 128-bit long
  doubles.
  
  [1] https://github.com/riscv/riscv-gcc/commit/54b21fc5ae83cefec44bc2caed4a8c664c274ba0
  
  PR:		242067
  Reported by:	Dennis Clarke <dclarke at blastwave.org>
  MFC after:	1 week
  Differential Revision:	https://reviews.freebsd.org/D25420

Modified:
  head/lib/libc/riscv/_fpmath.h

Modified: head/lib/libc/riscv/_fpmath.h
==============================================================================
--- head/lib/libc/riscv/_fpmath.h	Mon Jun 29 18:06:00 2020	(r362787)
+++ head/lib/libc/riscv/_fpmath.h	Mon Jun 29 19:30:35 2020	(r362788)
@@ -46,19 +46,6 @@ union IEEEl2bits {
 #define	LDBL_IMPLICIT_NBIT
 #define	mask_nbit_l(u)	((void)0)
 
-#define	LDBL_MANH_SIZE	20
-#define	LDBL_MANL_SIZE	32
-
-#define	LDBL_TO_ARRAY32(u, a) do {			\
-	(a)[0] = (uint32_t)(u).bits.manl;		\
-	(a)[1] = (uint32_t)(u).bits.manh;		\
-} while(0)
-
-/*
- * TODO: Due to compiler problem we are temporary using
- * LDBL_PREC == 53. Use code below for LDBL_PREC == 113
- */
-#if 0
 #define	LDBL_MANH_SIZE	48
 #define	LDBL_MANL_SIZE	64
 
@@ -68,4 +55,3 @@ union IEEEl2bits {
 	(a)[2] = (uint32_t)(u).bits.manh;		\
 	(a)[3] = (uint32_t)((u).bits.manh >> 32);	\
 } while(0)
-#endif