https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63264
Bug ID: 63264 Summary: Internal error due to invalid assembler register specification Product: gcc Version: 4.9.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: mikulas at artax dot karlin.mff.cuni.cz Host: x86_64-linux-gnux32 Target: x86_64-linux-gnux32 Build: x86_64-linux-gnux32 This piece of code: void f(unsigned x) { __asm__ volatile ("xorl %R0, %R0":"=r"(x):"r"(x):"cc"); } triggers this internal error: asm-crash.c: In function 'f': asm-crash.c:4:1: internal compiler error: in ix86_print_operand, at config/i386/i386.c:15214 } ^ Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. The error happens in i386, x86-64 and x32 mode. With or without optimization.