https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97971
Bug ID: 97971 Summary: [9/10/11 Regression] ICE in process_alt_operands, at lra-constraints.c:3110 Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: gs...@t-online.de Target Milestone: --- Started with r9 between 20181104 and 20181111 : $ cat z1.c int f () { register _Complex a asm ("rax"); register int b asm ("rdx"); asm ("abc %0 %1" : "=&r" (a), "=r" (b)); return a; } $ gcc-11-20201122 -c z1.c z1.c: In function 'f': z1.c:7:1: error: unable to generate reloads for impossible constraints: 7 | } | ^ (insn 5 2 6 2 (parallel [ (set (reg/v:DC 0 ax [ a ]) (asm_operands:DC ("abc %0 %1") ("=&r") 0 [] [] [] z1.c:5)) (set (reg/v:SI 1 dx [ b ]) (asm_operands:SI ("abc %0 %1") ("=r") 1 [] [] [] z1.c:5)) (clobber (reg:CC 17 flags)) ]) "z1.c":5:3 -1 (expr_list:REG_UNUSED (reg:CC 17 flags) (expr_list:REG_UNUSED (reg/v:SI 1 dx [ b ]) (expr_list:REG_UNUSED (reg:DI 1 dx) (nil))))) during RTL pass: reload z1.c:7:1: internal compiler error: in process_alt_operands, at lra-constraints.c:3110 0x5f12f5 _fatal_insn(char const*, rtx_def const*, char const*, int, char const*) ../../gcc/rtl-error.c:108 0x9de587 process_alt_operands ../../gcc/lra-constraints.c:3109 0x9e190b curr_insn_transform ../../gcc/lra-constraints.c:4073 0x9e4646 lra_constraints(bool) ../../gcc/lra-constraints.c:5138 0x9d28e2 lra(_IO_FILE*) ../../gcc/lra.c:2331 0x98dde9 do_reload ../../gcc/ira.c:5802 0x98dde9 execute ../../gcc/ira.c:5988