CHAPTER 17. FLOATING-POINT UNIT CHAPTER 17. FLOATING-POINT UNIT
JPEwasn’t triggered, soFLDloads the value ofa(5.6) inST(0):
Figure 17.15:OllyDbg: secondFLDexecutedThe function finishes its work.
Optimizing MSVC 2010
Listing 17.11: Optimizing MSVC 2010_a$ = 8 ; size = 8
_b$ = 16 ; size = 8
_d_max PROC
fld QWORD PTR _b$[esp-4]
fld QWORD PTR _a$[esp-4]
; current stack state: ST(0) = _a, ST(1) = _b
fcom ST(1) ; compare _a and ST(1) = (_b)
fnstsw ax
test ah, 65 ; 00000041H
jne SHORT $LN5@d_max
; copy ST(0) to ST(1) and pop register,
; leave (_a) on top
fstp ST(1)
; current stack state: ST(0) = _a
ret 0
$LN5@d_max:
; copy ST(0) to ST(0) and pop register,
; leave (_b) on top
fstp ST(0)
; current stack state: ST(0) = _b