When compiling in 32-bit mode using the "r", "S" or "D" asm constraint with a char variable gcc will incorrectly emit %sil or %dil
/* uses %sil for e */ void func(int a, int b, int c, int d, char e) { __asm__ volatile("%0 %1 %2 %3 %4" :: "r"(a), "r"(b), "r"(c), "r"(d), "r"(e)); } void func(char c) { __asm__ volatile("%0" :: "S"(c)); } This occurs with gcc version 4.4.0 20081021 (experimental) svn revision 141272 and gcc version 4.3.2 (Debian 4.3.2-1) Command line options used: -O2 -m32 -S -- Summary: %sil and %dil are used in 32-bit mode as inline asm registers Product: gcc Version: 4.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: inline-asm AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: therealfroggey at gmail dot com GCC build triplet: x86_64-linux-gnu GCC host triplet: x86_64-linux-gnu GCC target triplet: x86_64-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37887