From 4cf2c9baeabf8b64b36170d864ec44e7215a89df Mon Sep 17 00:00:00 2001
From: Mike Pavone <pavone@retrodev.com>
Date: Thu, 3 Oct 2013 21:21:47 -0700
Subject: Follow amd64 ABI stack alignment requirements in places it matters so
 we can call sprintf with floating point arguments without crashing

---
 runtime.S | 38 +++++++++++++++++++++++++++-----------
 1 file changed, 27 insertions(+), 11 deletions(-)

(limited to 'runtime.S')

diff --git a/runtime.S b/runtime.S
index 357eabe..36ecfff 100644
--- a/runtime.S
+++ b/runtime.S
@@ -10,14 +10,22 @@ do_sync:
 	call m68k_save_context
 	mov %rsi, %rdi
 	xor %esi, %esi
+	test $8, %esp
+	jnz adjust_rsp
 	call sync_components
+	jmp done_adjust
+adjust_rsp:
+	sub $8, %rsp
+	call sync_components
+	add $8, %rsp
+done_adjust:
 	mov %rax, %rsi
 	call m68k_load_context
 	pop %rdi
 	pop %rcx
 skip_sync:
 	ret
-	
+
 sr_msg_int:
 	.asciz "SR set to $%X due to interrupt\n"
 debug_print_sr_int:
@@ -47,7 +55,7 @@ debug_print_sr:
 
 invalid_msg:
 	.asciz "Invalid instruction at %X\n"
-	
+
 	.global m68k_invalid
 m68k_invalid:
 	lea invalid_msg(%rip), %rdi
@@ -60,7 +68,7 @@ m68k_invalid:
 	.global bcd_add
 bcd_add:
 	xchg %rax, %rdi
-	
+
 	mov %cl, %ch
 	mov %al, %ah
 	and $0xF, %ch
@@ -82,14 +90,14 @@ def_adjust:
 	add $0x60, %cl
 	mov $1, %ch
 no_adjust_h:
-	
+
 	mov %rdi, %rax
 	ret
 
 	.global bcd_sub
 bcd_sub:
 	xchg %rax, %rdi
-	
+
 	mov %cl, %ch
 	mov %al, %ah
 	and $0xF, %ch
@@ -111,7 +119,7 @@ def_adjusts:
 	sub $0x60, %cl
 	mov $1, %ch
 no_adjust_hs:
-	
+
 	mov %rdi, %rax
 	ret
 
@@ -168,7 +176,7 @@ set_ccr:
 	and $1, %cl
 	mov %cl, (%rsi)
 	ret
-	
+
 	.global m68k_modified_ret_addr
 m68k_modified_ret_addr:
 	add $16, %rsp
@@ -181,7 +189,15 @@ m68k_native_addr_and_sync:
 	push %rcx
 	mov %rsi, %rdi
 	xor %esi, %esi
+	test $8, %rsp
+	jnz adjust_rsp_na
+	call sync_components
+	jmp no_adjust_rsp_na
+adjust_rsp_na:
+	sub $8, %rsp
 	call sync_components
+	add $8, %rsp
+no_adjust_rsp_na:
 	pop %rsi
 	push %rax
 	mov %rax, %rdi
@@ -202,7 +218,7 @@ m68k_native_addr:
 	pop %rsi
 	call m68k_load_context
 	ret
-	
+
 	.global m68k_retrans_stub
 m68k_retrans_stub:
 	call m68k_save_context
@@ -255,15 +271,15 @@ m68k_start_context:
 	push %r13
 	push %r14
 	push %r15
-	
+
 	call m68k_load_context
 	call *%rdi
 	call m68k_save_context
-	
+
 	pop %r15
 	pop %r14
 	pop %r13
 	pop %r12
 	pop %rbp
-	
+
 	ret
-- 
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