diff --git a/vm/callstack.hpp b/vm/callstack.hpp
index ae1e80ca9a..1ea98f883c 100755
--- a/vm/callstack.hpp
+++ b/vm/callstack.hpp
@@ -13,7 +13,7 @@ PRIMITIVE(innermost_stack_frame_executing);
 PRIMITIVE(innermost_stack_frame_scan);
 PRIMITIVE(set_innermost_stack_frame_quot);
 
-VM_ASM_API void save_callstack_bottom(stack_frame *callstack_bottom,factor_vm *vm);
+VM_ASM_API void save_callstack_bottom(stack_frame *callstack_bottom, factor_vm *vm);
 
 
 }
diff --git a/vm/cpu-ppc.hpp b/vm/cpu-ppc.hpp
index d0036fb84f..495eb375ec 100644
--- a/vm/cpu-ppc.hpp
+++ b/vm/cpu-ppc.hpp
@@ -3,7 +3,6 @@ namespace factor
 
 #define FACTOR_CPU_STRING "ppc"
 #define VM_ASM_API VM_C_API
-#define VM_ASM_API_OVERFLOW VM_C_API
 
 register cell ds asm("r13");
 register cell rs asm("r14");
diff --git a/vm/cpu-x86.32.S b/vm/cpu-x86.32.S
index 3eeb798093..4f06de1ce7 100644
--- a/vm/cpu-x86.32.S
+++ b/vm/cpu-x86.32.S
@@ -82,7 +82,7 @@ DEF(void,set_x87_env,(const void*)):
 	ret
 
 DEF(F_FASTCALL void,throw_impl,(CELL quot, F_STACK_FRAME *rewind_to, void *vm)):
-	mov CELL_SIZE(STACK_REG),NV_TEMP_REG  /* get vm ptr in case quot_xt = lazy_jit_compile */		
+	mov ARG2,NV_TEMP_REG  /* remember vm ptr in case quot_xt = lazy_jit_compile */		
 	/* clear x87 stack, but preserve rounding mode and exception flags */
 	sub $2,STACK_REG
 	fnstcw (STACK_REG)
diff --git a/vm/cpu-x86.32.hpp b/vm/cpu-x86.32.hpp
index a95179a49b..e740771470 100644
--- a/vm/cpu-x86.32.hpp
+++ b/vm/cpu-x86.32.hpp
@@ -6,6 +6,5 @@ namespace factor
 register cell ds asm("esi");
 register cell rs asm("edi");
 
-#define VM_ASM_API VM_C_API __attribute__ ((regparm (2)))
-#define VM_ASM_API_OVERFLOW VM_C_API __attribute__ ((regparm (3)))
+#define VM_ASM_API VM_C_API __attribute__ ((regparm (3)))
 }
diff --git a/vm/cpu-x86.64.hpp b/vm/cpu-x86.64.hpp
index 841705c171..75d432ee13 100644
--- a/vm/cpu-x86.64.hpp
+++ b/vm/cpu-x86.64.hpp
@@ -7,5 +7,4 @@ register cell ds asm("r14");
 register cell rs asm("r15");
 
 #define VM_ASM_API VM_C_API
-#define VM_ASM_API_OVERFLOW VM_C_API
 }
diff --git a/vm/cpu-x86.hpp b/vm/cpu-x86.hpp
index 8fe0cc4b10..9074bc1a71 100644
--- a/vm/cpu-x86.hpp
+++ b/vm/cpu-x86.hpp
@@ -69,7 +69,7 @@ inline static unsigned int fpu_status(unsigned int status)
 }
 
 /* Defined in assembly */
-VM_ASM_API void c_to_factor(cell quot,void *vm);
+VM_ASM_API void c_to_factor(cell quot, void *vm);
 VM_ASM_API void throw_impl(cell quot, stack_frame *rewind_to, void *vm);
 VM_ASM_API void lazy_jit_compile(cell quot, void *vm);
 
diff --git a/vm/math.cpp b/vm/math.cpp
index 61ec096c59..638d9fa85c 100755
--- a/vm/math.cpp
+++ b/vm/math.cpp
@@ -838,7 +838,7 @@ inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 		untag_fixnum(x) + untag_fixnum(y))));
 }
 
-VM_ASM_API_OVERFLOW void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *myvm)
+VM_ASM_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *myvm)
 {
 	PRIMITIVE_OVERFLOW_GETVM()->overflow_fixnum_add(x,y);
 }
@@ -849,7 +849,7 @@ inline void factor_vm::overflow_fixnum_subtract(fixnum x, fixnum y)
 		untag_fixnum(x) - untag_fixnum(y))));
 }
 
-VM_ASM_API_OVERFLOW void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *myvm)
+VM_ASM_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *myvm)
 {
 	PRIMITIVE_OVERFLOW_GETVM()->overflow_fixnum_subtract(x,y);
 }
@@ -863,7 +863,7 @@ inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 	drepl(tag<bignum>(bignum_multiply(bx,by)));
 }
 
-VM_ASM_API_OVERFLOW void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *myvm)
+VM_ASM_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *myvm)
 {
 	PRIMITIVE_OVERFLOW_GETVM()->overflow_fixnum_multiply(x,y);
 }
diff --git a/vm/math.hpp b/vm/math.hpp
index a82a9a9580..f81de37650 100644
--- a/vm/math.hpp
+++ b/vm/math.hpp
@@ -83,8 +83,8 @@ VM_C_API u64 to_unsigned_8(cell obj, factor_vm *vm);
 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *vm);
 VM_C_API cell to_cell(cell tagged, factor_vm *vm);
 
-VM_ASM_API_OVERFLOW void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *vm);
-VM_ASM_API_OVERFLOW void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *vm);
-VM_ASM_API_OVERFLOW void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *vm);
+VM_ASM_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *vm);
+VM_ASM_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *vm);
+VM_ASM_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *vm);
 
 }
diff --git a/vm/quotations.cpp b/vm/quotations.cpp
index e5a2a53f86..1bc6240481 100755
--- a/vm/quotations.cpp
+++ b/vm/quotations.cpp
@@ -368,7 +368,7 @@ cell factor_vm::lazy_jit_compile_impl(cell quot_, stack_frame *stack)
 	return quot.value();
 }
 
-VM_ASM_API_OVERFLOW cell lazy_jit_compile_impl(cell quot_, stack_frame *stack, factor_vm *myvm)
+VM_ASM_API cell lazy_jit_compile_impl(cell quot_, stack_frame *stack, factor_vm *myvm)
 {
 	ASSERTVM();
 	return VM_PTR->lazy_jit_compile_impl(quot_,stack);
diff --git a/vm/quotations.hpp b/vm/quotations.hpp
index 43beb05112..b21884a35b 100755
--- a/vm/quotations.hpp
+++ b/vm/quotations.hpp
@@ -27,7 +27,7 @@ PRIMITIVE(jit_compile);
 PRIMITIVE(array_to_quotation);
 PRIMITIVE(quotation_xt);
 
-VM_ASM_API_OVERFLOW cell lazy_jit_compile_impl(cell quot, stack_frame *stack, factor_vm *myvm);
+VM_ASM_API cell lazy_jit_compile_impl(cell quot, stack_frame *stack, factor_vm *myvm);
 
 PRIMITIVE(quot_compiled_p);