From 2f4d895197e7b137f50624bef58c9b614bf081e5 Mon Sep 17 00:00:00 2001
From: Jim Wilson <jimw@sifive.com>
Date: Sat, 7 Sep 2019 00:09:21 +0000
Subject: [PATCH] RISC-V: Re-enable -msave-restore for shared libraries.

This re-enables -msave-restore for shared libraries, and uses the
t-slibgcc-libgcc file to get the save-restore routines included directly
in shared libraries so that we don't need to indirect through the PLT
to reach them, which doesn't work.

	gcc/
	* config/riscv/riscv.c (riscv_option_override): Revert 2019-08-30
	change.

	libgcc/
	* config.host (riscv*-*-linux*): Add t-slibgcc-libgcc to tmake_file.
	(riscv*-*-freebsd*): Likewise.

From-SVN: r275478
---
 gcc/ChangeLog            |  5 +++++
 gcc/config/riscv/riscv.c | 10 ----------
 libgcc/ChangeLog         |  5 +++++
 libgcc/config.host       |  4 ++--
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 91069bff50a..46c1b50346e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-09-06  Jim Wilson  <jimw@sifive.com>
+
+	* config/riscv/riscv.c (riscv_option_override): Revert 2019-08-30
+	change.
+
 2019-09-06  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* config/rs6000/rs6000.md (unspec): Delete UNSPEC_MV_CR_OV.
diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c
index 1e7528f1cb9..9b16a1eb9c2 100644
--- a/gcc/config/riscv/riscv.c
+++ b/gcc/config/riscv/riscv.c
@@ -4636,16 +4636,6 @@ riscv_option_override (void)
     error ("%<-mriscv-attribute%> RISC-V ELF attribute requires GNU as 2.32"
 	   " [%<-mriscv-attribute%>]");
 #endif
-
-  /* The save-restore routines use t0 which is clobbered by the plt header,
-     so we can't use them when building shared libraries.  */
-  if (TARGET_SAVE_RESTORE && flag_pic && TARGET_PLT)
-    {
-      target_flags &= ~MASK_SAVE_RESTORE;
-      if (target_flags_explicit & MASK_SAVE_RESTORE)
-	warning (0, "%<-msave-restore%> disabled; not supported with PLT "
-		 "based shared libraries");
-    }
 }
 
 /* Implement TARGET_CONDITIONAL_REGISTER_USAGE.  */
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 1ffb236add2..df5d99684e6 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-09-06  Jim Wilson  <jimw@sifive.com>
+
+	* config.host (riscv*-*-linux*): Add t-slibgcc-libgcc to tmake_file.
+	(riscv*-*-freebsd*): Likewise.
+
 2019-09-03  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* config.host: Remove references to spu.
diff --git a/libgcc/config.host b/libgcc/config.host
index a3976702ab5..1db52878a5e 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1201,12 +1201,12 @@ pru-*-*)
 	tm_file="$tm_file pru/pru-abi.h"
 	;;
 riscv*-*-linux*)
-	tmake_file="${tmake_file} riscv/t-softfp${host_address} t-softfp riscv/t-elf riscv/t-elf${host_address}"
+	tmake_file="${tmake_file} riscv/t-softfp${host_address} t-softfp riscv/t-elf riscv/t-elf${host_address} t-slibgcc-libgcc"
 	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o crtendS.o crtbeginT.o"
 	md_unwind_header=riscv/linux-unwind.h
 	;;
 riscv*-*-freebsd*)
-	tmake_file="${tmake_file} riscv/t-softfp${host_address} t-softfp riscv/t-elf riscv/t-elf${host_address}"
+	tmake_file="${tmake_file} riscv/t-softfp${host_address} t-softfp riscv/t-elf riscv/t-elf${host_address} t-slibgcc-libgcc"
 	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o crtendS.o crtbeginT.o"
 	;;
 riscv*-*-*)