[PATCH] lib: add setjmp/longjmp for riscv64

[Ekaitz Zarraga]

>From 456fe2e37a29b445d9aa3163c82279fb7b1c2162 Mon Sep 17 00:00:00 2001
From: Ekaitz Zarraga <ekaitz@elenq.tech>
Date: Wed, 18 Oct 2023 14:41:46 +0200
Subject: [PATCH] lib: add setjmp/longjmp for riscv64

Note about the -tcc file:

    HAVE_FLOAT_ASM defines if there's assembly support for float
    instructions.

    HAVE_FLOAT defines if there's floating point arithmetic support.

    This is important for TinyCC because the assembler and the C
    compiler are split. TinyCC can HAVE_FLOAT but no assembler support
    for them.

* lib/riscv64-mes-gcc/setjmp.c: Add file
* lib/riscv64-mes-tcc/setjmp.c: Add file
---
 lib/riscv64-mes-gcc/setjmp.c | 70 +++++++++++++++++++++++---
 lib/riscv64-mes-tcc/setjmp.c | 97 ++++++++++++++++++++++++++++++++++++
 2 files changed, 160 insertions(+), 7 deletions(-)
 create mode 100644 lib/riscv64-mes-tcc/setjmp.c

diff --git a/lib/riscv64-mes-gcc/setjmp.c b/lib/riscv64-mes-gcc/setjmp.c
index 190c1a19..dae21fa0 100644
--- a/lib/riscv64-mes-gcc/setjmp.c
+++ b/lib/riscv64-mes-gcc/setjmp.c
@@ -2,6 +2,7 @@
  * GNU Mes --- Maxwell Equations of Software
  * Copyright © 2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
  * Copyright © 2021 W. J. van der Laan <laanwj@protonmail.com>
+ * Copyright © 2023 Ekaitz Zarraga <ekaitz@elenq.tech>
  *
  * This file is part of GNU Mes.
  *
@@ -22,19 +23,74 @@
 #include <setjmp.h>
 #include <stdlib.h>
 
-/* This doesn't do anything at the moment.
- * According to setjmp.h "It is not supported to use mes' setjmp 
implementation together with GCC."
- * We cannot offer this functionality as a C function. It remains to be done 
(as assembly) for tcc.
- */
-
 void
 longjmp (jmp_buf env, int val)
 {
-  exit (42);
+    val = val == 0 ? 1 : val;
+    asm(
+    "ld s0,    0(a0)\n\t"
+    "ld s1,    8(a0)\n\t"
+    "ld s2,    16(a0)\n\t"
+    "ld s3,    24(a0)\n\t"
+    "ld s4,    32(a0)\n\t"
+    "ld s5,    40(a0)\n\t"
+    "ld s6,    48(a0)\n\t"
+    "ld s7,    56(a0)\n\t"
+    "ld s8,    64(a0)\n\t"
+    "ld s9,    72(a0)\n\t"
+    "ld s10,   80(a0)\n\t"
+    "ld s11,   88(a0)\n\t"
+    "ld sp,    96(a0)\n\t"
+    "ld ra,    104(a0)\n\t"
+#ifndef __riscv_float_abi_soft
+    "fld fs0,  112(a0)\n\t"
+    "fld fs1,  120(a0)\n\t"
+    "fld fs2,  128(a0)\n\t"
+    "fld fs3,  136(a0)\n\t"
+    "fld fs4,  144(a0)\n\t"
+    "fld fs5,  152(a0)\n\t"
+    "fld fs6,  160(a0)\n\t"
+    "fld fs7,  168(a0)\n\t"
+    "fld fs8,  176(a0)\n\t"
+    "fld fs9,  184(a0)\n\t"
+    "fld fs10, 192(a0)\n\t"
+    "fld fs11, 200(a0)\n\t"
+#endif
+    );
 }
 
 int
 setjmp (jmp_buf env)
 {
-  return -1;
+    asm(
+    "sd s0,   0(a0)\n\t"
+    "sd s1,   8(a0)\n\t"
+    "sd s2,   16(a0)\n\t"
+    "sd s3,   24(a0)\n\t"
+    "sd s4,   32(a0)\n\t"
+    "sd s5,   40(a0)\n\t"
+    "sd s6,   48(a0)\n\t"
+    "sd s7,   56(a0)\n\t"
+    "sd s8,   64(a0)\n\t"
+    "sd s9,   72(a0)\n\t"
+    "sd s10,  80(a0)\n\t"
+    "sd s11,  88(a0)\n\t"
+    "sd sp,   96(a0)\n\t"
+    "sd ra,   104(a0)\n\t"
+#ifndef __riscv_float_abi_soft
+    "fsd fs0,  112(a0)\n\t"
+    "fsd fs1,  120(a0)\n\t"
+    "fsd fs2,  128(a0)\n\t"
+    "fsd fs3,  136(a0)\n\t"
+    "fsd fs4,  144(a0)\n\t"
+    "fsd fs5,  152(a0)\n\t"
+    "fsd fs6,  160(a0)\n\t"
+    "fsd fs7,  168(a0)\n\t"
+    "fsd fs8,  176(a0)\n\t"
+    "fsd fs9,  184(a0)\n\t"
+    "fsd fs10, 192(a0)\n\t"
+    "fsd fs11, 200(a0)\n\t"
+#endif
+    );
+  return 0;
 }
diff --git a/lib/riscv64-mes-tcc/setjmp.c b/lib/riscv64-mes-tcc/setjmp.c
new file mode 100644
index 00000000..96434d94
--- /dev/null
+++ b/lib/riscv64-mes-tcc/setjmp.c
@@ -0,0 +1,97 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ * Copyright © 2021 W. J. van der Laan <laanwj@protonmail.com>
+ * Copyright © 2023 Ekaitz Zarraga <ekaitz@elenq.tech>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <setjmp.h>
+#include <stdlib.h>
+
+void
+longjmp (jmp_buf env, int val)
+{
+    val = val == 0 ? 1 : val;
+    asm(
+    "ld s0, a0,0\n\t"
+    "ld s1, a0,8\n\t"
+    "ld s2, a0,16\n\t"
+    "ld s3, a0,24\n\t"
+    "ld s4, a0,32\n\t"
+    "ld s5, a0,40\n\t"
+    "ld s6, a0,48\n\t"
+    "ld s7, a0,56\n\t"
+    "ld s8, a0,64\n\t"
+    "ld s9, a0,72\n\t"
+    "ld s10,a0,80\n\t"
+    "ld s11,a0,88\n\t"
+    "ld sp, a0,96\n\t"
+    "ld ra, a0,104\n\t"
+#if HAVE_FLOAT_ASM && HAVE_FLOAT && ! __riscv_float_abi_soft
+    "fld fs0, a0,112\n\t"
+    "fld fs1, a0,120\n\t"
+    "fld fs2, a0,128\n\t"
+    "fld fs3, a0,136\n\t"
+    "fld fs4, a0,144\n\t"
+    "fld fs5, a0,152\n\t"
+    "fld fs6, a0,160\n\t"
+    "fld fs7, a0,168\n\t"
+    "fld fs8, a0,176\n\t"
+    "fld fs9, a0,184\n\t"
+    "fld fs10,a0,192\n\t"
+    "fld fs11,a0,200\n\t"
+#endif
+    );
+}
+
+int
+setjmp (jmp_buf env)
+{
+    asm(
+    "sd  a0, s0,0\n\t"
+    "sd  a0, s1,8\n\t"
+    "sd  a0, s2,16\n\t"
+    "sd  a0, s3,24\n\t"
+    "sd  a0, s4,32\n\t"
+    "sd  a0, s5,40\n\t"
+    "sd  a0, s6,48\n\t"
+    "sd  a0, s7,56\n\t"
+    "sd  a0, s8,64\n\t"
+    "sd  a0, s9,72\n\t"
+    "sd  a0, s10,80\n\t"
+    "sd  a0, s11,88\n\t"
+    "sd  a0, sp,96\n\t"
+    "sd  a0, ra,104\n\t"
+#if HAVE_FLOAT_ASM && HAVE_FLOAT && ! __riscv_float_abi_soft
+    "fsd a0, fs0,112\n\t"
+    "fsd a0, fs1,120\n\t"
+    "fsd a0, fs2,128\n\t"
+    "fsd a0, fs3,136\n\t"
+    "fsd a0, fs4,144\n\t"
+    "fsd a0, fs5,152\n\t"
+    "fsd a0, fs6,160\n\t"
+    "fsd a0, fs7,168\n\t"
+    "fsd a0, fs8,176\n\t"
+    "fsd a0, fs9,184\n\t"
+    "fsd a0, fs10,192\n\t"
+    "fsd a0, fs11,200\n\t"
+#endif
+    );
+  return 0;
+}
+
-- 
2.41.0