https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103926
Bug ID: 103926 Summary: "wQ" broken Product: gcc Version: 11.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: other Assignee: unassigned at gcc dot gnu.org Reporter: aik at ozlabs dot ru CC: segher at gcc dot gnu.org Target Milestone: --- Host: power8 Target: powerpc64le-linux Build: 3b0ba97fafe8 (2 week old releases/gcc-11) Using `wQ` constraint ("memory acceptable by `lq`") makes gcc crash. Note that without "-O2" gcc gently fails (not sure why). The issue recreates on gcc-11 from git and Ubuntu 2104's gcc (10.3.0-1ubuntu1). [fstn1-p1 ~]$ /home/aik/pbuild/crossgcc/gcc-powerpc64le-linux-11.2.1-2.37.50-nolibc/bin/powerpc64le-linux-gcc gccbug.c -o gccbug.o -O2 gccbug.c: In function âfâ: gccbug.c:6:1: error: unrecognizable insn: 6 | } | ^ (insn 6 11 9 2 (parallel [ (set (reg:TI 10 10 [orig:118 v ] [118]) (asm_operands/v:TI ("lq %0, 0(%1)") ("=&r") 0 [ (mem/f/c:DI (reg:DI 9 9 [120]) [1 ptr+0 S8 A128]) ] [ (asm_input:DI ("wQ") gccbug.c:5) ] [] gccbug.c:5)) (clobber (reg:SI 98 ca)) ]) "gccbug.c":5:2 -1 (nil)) during RTL pass: postreload gccbug.c:6:1: internal compiler error: in extract_constrain_insn, at recog.c:2671 0x10190343 _fatal_insn(char const*, rtx_def const*, char const*, int, char const*) /home/aik/p/gcc/gcc/gcc/rtl-error.c:108 0x10190397 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*) /home/aik/p/gcc/gcc/gcc/rtl-error.c:116 0x1082fe6b extract_constrain_insn(rtx_insn*) /home/aik/p/gcc/gcc/gcc/recog.c:2671 0x107ea1bf reload_cse_simplify_operands /home/aik/p/gcc/gcc/gcc/postreload.c:407 0x107ebd5f reload_cse_simplify /home/aik/p/gcc/gcc/gcc/postreload.c:190 0x107ebd5f reload_cse_regs_1 /home/aik/p/gcc/gcc/gcc/postreload.c:238 0x107edf7b reload_cse_regs /home/aik/p/gcc/gcc/gcc/postreload.c:66 0x107edf7b execute /home/aik/p/gcc/gcc/gcc/postreload.c:2359 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. [fstn1-p1 ~]$ cat gccbug.c void f(void) { void *ptr; __int128 v; asm volatile("lq %0, 0(%1)" : "=&r" (v) : "wQ" (ptr)); }