svn commit: r353334 - head/lib/libthr/arch/riscv/include

[Mitchell Horne]

Author: mhorne
Date: Wed Oct  9 02:02:22 2019
New Revision: 353334
URL: https://svnweb.freebsd.org/changeset/base/353334

Log:
  RISC-V: Fix an alignment warning in libthr
  
  Compiling with clang gives a loss-of-alignment error due the cast to
  uint8_t *. Since the TLS is always tcb aligned and TP_OFFSET is defined
  as sizeof(struct tcb) we can guarantee there is no misalignment. Silence
  the error by moving the offset into the inline assembly.
  
  Reviewed by:	br
  MFC after:	1 week
  Differential Revision:	https://reviews.freebsd.org/D21926

Modified:
  head/lib/libthr/arch/riscv/include/pthread_md.h

Modified: head/lib/libthr/arch/riscv/include/pthread_md.h
==============================================================================
--- head/lib/libthr/arch/riscv/include/pthread_md.h	Tue Oct  8 23:52:04 2019	(r353333)
+++ head/lib/libthr/arch/riscv/include/pthread_md.h	Wed Oct  9 02:02:22 2019	(r353334)
@@ -62,7 +62,7 @@ static __inline void
 _tcb_set(struct tcb *tcb)
 {
 
-	__asm __volatile("mv tp, %0" :: "r"((uint8_t *)tcb + TP_OFFSET));
+	__asm __volatile("addi tp, %0, %1" :: "r"(tcb), "I"(TP_OFFSET));
 }
 
 /*
@@ -71,11 +71,11 @@ _tcb_set(struct tcb *tcb)
 static __inline struct tcb *
 _tcb_get(void)
 {
-	register uint8_t *_tp;
+	struct tcb *_tcb;
 
-	__asm __volatile("mv %0, tp" : "=r"(_tp));
+	__asm __volatile("addi %0, tp, %1" : "=r"(_tcb) : "I"(-TP_OFFSET));
 
-	return ((struct tcb *)(_tp - TP_OFFSET));
+	return (_tcb);
 }
 
 static __inline struct pthread *