From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 8 Jul 2015 20:46:52 -0400
Subject: Initial commit

---
 unix/as.linuxppc/README | 68 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 unix/as.linuxppc/README

(limited to 'unix/as.linuxppc/README')

diff --git a/unix/as.linuxppc/README b/unix/as.linuxppc/README
new file mode 100644
index 00000000..d19b2a3e
--- /dev/null
+++ b/unix/as.linuxppc/README
@@ -0,0 +1,68 @@
+# LinuxPPC Assembler - LinuxPPC 2000, Aug 2000
+
+	.file	"zz.c"
+# zsvjmp_(buf,status)
+# int *buf;
+# int *status;
+# {
+#	 *status = 0;
+#	 buf[0] = *status;
+#	 setjmp (&buf[1]);
+# }
+
+gcc2_compiled.:
+	.section	".text"
+	.align 2
+	.globl zsvjmp_
+	.type	 zsvjmp_,@function
+
+	# Addressing: 12(31) means effective address (EA) is r31+12
+	# lwz 9,12(31) means move value at EA to r9
+
+	# REGISTERS: r1 = stack pointer, r31 = frame pointer, r3+ = args
+	# Function always saves r1, r31 on stack.  Sets up frame with
+	# required auto storage.  Saves LR as well if any functions will
+	# be called.
+
+zsvjmp_:
+	# -- Push old r1 on stack; start new stack frame at r1
+	stwu 1,-32(1)		# Store word with update (push on stack)
+				# EA = r1-32;  (r1) -> (EA), EA -> r1
+
+	# -- Save LR, r31 in stack frame
+	mflr 0			# Move from Link Register:  LR -> r0
+	stw 31,28(1)		# Store word:              r31 -> r1+28
+	stw 0,36(1)		# Store word:               r0 -> r1+36
+
+	# -- Save r3 (arg1), r4 (arg2) on stack
+	mr  31,1		# Move register:            r1 -> r31
+	stw 3,8(31)		#                           r3 -> r31+8
+	stw 4,12(31)		#		            r4 -> r31+12
+
+	# -- *status = 0;
+	lwz 9,12(31)		# Load word and zero: (r31+12) -> r9
+	li 0,0			# Load zero:		     0 -> r0
+	stw 0,0(9)		# Store:		    r0 -> r9+0
+
+	# -- buf[0] = *status;
+	lwz 9,8(31)		# buf -> r9
+	lwz 11,12(31)		# status -> r11
+	lwz 0,0(11)		# *status -> r0
+	stw 0,0(9)		# r0 -> buf[0]
+
+	# -- setjmp (&buf[1]);
+	lwz 9,8(31)		# buf -> r9
+	addi 0,9,4		# Add immediate;	  r9+4 -> r0
+	mr 3,0			# R3 is first arg
+	crxor 6,6,6		# Condition reg XOR: xor(b6,b6) -> b6
+	bl setjmp		# Branch to setjmp; addr(.L2) -> LR
+.L2:
+	lwz 11,0(1)		# load old r1 into r11
+	lwz 0,4(11)		# load old LR into r0
+	mtlr 0			# restore return addr to LR
+	lwz 31,-4(11)		# restore old r31
+	mr 1,11			# restore old r1
+	blr			# Branch unconditionally (to LR addr)
+.Lfe1:
+	.size	 zsvjmp_,.Lfe1-zsvjmp_
+	.ident	"GCC: (GNU) 2.95.2 19991024 (release/franzo)"
-- 
cgit