This is the second of 3 related g++ bugs concerning regparm(3) on ix86. Problem: g++ 3.4.6, 4.0.4, 4.1.2 (and possibly others) pass wrong parameters on calls to pointer-to-member-functions tagged __attribute((regparm(3))). Test case: -------------------------------------------------- // compile on ix86 with: g++ -Wall -O extern "C" { int printf(const char * format, ...); } class Base; Base * save_this; int * save_addr1, * save_addr2; class Base { public: __attribute((regparm(3))) void set(int * addr1, int * addr2) { if ((void *)this != (void *)save_this) printf("error! this == %p, should be %p\n", this, save_this); if (addr1 != save_addr1) printf("error! addr1 == %p, should be %p\n", addr1, save_addr1); if (addr2 != save_addr2) printf("error! addr2 == %p, should be %p\n", addr2, save_addr1); } }; int main() { void (__attribute((regparm(3))) Base::* pfm)(int *, int *) = &Base::set; Base obj; save_this = &obj; int x, y; save_addr1 = &x; save_addr2 = &y; (obj.* pfm) (&x, &y); return 0; } -------------------------------------------------- Test case output: ---------------- g++ 3.4.6 ----------------------- error! this == 0x80484b0, should be 0xafa60cdf error! addr1 == 0x80484b0, should be 0xafa60cd8 -------------------------------------------------- ---------------- g++ 4.0.4 ----------------------- error! this == 0x80484b0, should be 0xaf9eb45f error! addr1 == 0x80484b0, should be 0xaf9eb458 -------------------------------------------------- ---------------- g++ 4.1.2 ----------------------- error! this == 0x80484b0, should be 0xafbe265f error! addr1 == 0x80484b0, should be 0xafbe2658 -------------------------------------------------- gcc versions tested: 3.4.6, 4.0.4, 4.1.2 >>>>> g++-3.4.6 -v <<<<< Reading specs from /usr/lib/gcc/i486-linux-gnu/3.4.6/specs Configured with: ../src/configure -v --enable-languages=c,c++,f77,pascal --prefix=/usr --libexecdir=/usr/lib --with-gxx-include-dir=/usr/include/c++/3.4 --enable-shared --with-system-zlib --enable-nls --without-included-gettext --program-suffix=-3.4 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --with-tune=i686 i486-linux-gnu Thread model: posix gcc version 3.4.6 (Debian 3.4.6-4) >>>>> g++-4.0.4 -v <<<<< Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,java --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.0 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-java-awt=gtk-default --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-4.0-1.4.2.0/jre --with-tune=i686 --enable-checking=release i486-linux-gnu Thread model: posix gcc version 4.0.4 20060904 (prerelease) (Debian 4.0.3-7) >>>>> g++-4.1.2 -v <<<<< Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --with-tune=i686 --enable-checking=release i486-linux-gnu Thread model: posix gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-20)
*** This bug has been marked as a duplicate of 9381 ***