From: Matt Birkholz <matt@birchwood-abbey.net>
Date: Tue, 12 Sep 2017 02:00:01 +0000 (-0700)
Subject: microcode/cmpauxmd/x86-64.m4: Restore frame pointer after callback.
X-Git-Tag: mit-scheme-pucked-9.2.12~74
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=2a9449cc143eb682be83717500889c06adf2fde6;p=mit-scheme.git

microcode/cmpauxmd/x86-64.m4: Restore frame pointer after callback.
---

diff --git a/src/microcode/cmpauxmd/x86-64.m4 b/src/microcode/cmpauxmd/x86-64.m4
index a03136cc4..d43e7ef60 100644
--- a/src/microcode/cmpauxmd/x86-64.m4
+++ b/src/microcode/cmpauxmd/x86-64.m4
@@ -472,11 +472,14 @@ ifdef(`WIN32',						# Register block = %rsi
 `	OP(lea,q)	TW(ABS(EVR(Registers)),regs)')
 	OP(mov,q)	TW(ABS(EVR(Free)),rfree)	# Free pointer = %rdi
 	OP(mov,q)	TW(QOF(REGBLOCK_VAL(),regs),REG(rax)) # Value/dynamic link
-	OP(mov,q)	TW(IMM(ADDRESS_MASK),rmask)	# = %rbp
 	# Restore the C stack pointer, which we zeroed back in
 	# scheme_to_interface, for within_c_stack.
+	# Restore the C frame pointer too; the interface may have called
+	# Re_Enter_Interpreter which probably clobbered both.
 	OP(mov,q)	TW(REG(rsp),ABS(EVR(C_Stack_Pointer)))
 	OP(mov,q)	TW(ABS(EVR(stack_pointer)),REG(rsp))
+	OP(mov,q)	TW(REG(rbp),ABS(EVR(C_Frame_Pointer)))
+	OP(mov,q)	TW(IMM(ADDRESS_MASK),rmask)	# = %rbp
 	OP(mov,q)	TW(REG(rax),REG(rcx))		# Preserve if used
 	OP(and,q)	TW(rmask,REG(rcx))		# Restore potential dynamic link
 	OP(mov,q)	TW(REG(rcx),QOF(REGBLOCK_DLINK(),regs))