Most probably it generates invalid opcode. Need to check that with disassembler. On 22 July 2012 05:27, Lawson English <lenglish5@cox.net> wrote:

Still playing with Native Boost assembler.

This code instantly crashes Pharo 1.4 with NB installed:

TestAssem swapDoubFirst: 1.0 withSecond: 2.0.

TestAssem>>swapDoubFirst: r1 withSecond: r2

<primitive: #primitiveNativeCall module: #NativeBoostPlugin>

^ NBFFICallout cdecl: #( double ( double r1, double r2 )) emitCall: [:gen | | asm proxy smpfr scnt| asm := gen asm. proxy := gen proxy.

asm pop: asm ECX. asm fld: asm ESP ptr64 . asm fld: asm ESP ptr64 + 8 .

asm fxch: asm ST0. ]

-- Squeak from the very start (introduction to Squeak and Pharo Smalltalk for the (almost) complete and compleate beginner). https://www.youtube.com/playlist?list=PL6601A198DF14788D&feature=view_all

-- Best regards, Igor Stasenko.