I am enclosing a small test case. This is on Cray T3E, big endian alpha. ---- source code ----
#define SHARED_PTR_SIZE 128 #define SHARED_PTR_PHASE_SIZE 48 #define SHARED_PTR_THREAD_SIZE 16 #define SHARED_PTR_VIRTADDR_SIZE 64 typedef struct shared_ptr_struct { unsigned long phase : SHARED_PTR_PHASE_SIZE; unsigned thread : SHARED_PTR_THREAD_SIZE; void *addr; } shared_ptr_t; typedef shared_ptr_t *shared_ptr_p; shared_ptr_t x; main () { x.thread = 2; } ----- error reported ----- > gcc -da -c alpha_bug.c alpha_bug.c: In function `main': alpha_bug.c:21: error: unrecognizable insn: (insn 14 13 15 0 (set (reg:DI 73) (plus:DI (plus:DI (reg/f:DI 71) (const_int 6 [0x6])) (const_int 1 [0x1]))) -1 (nil) (nil)) alpha_bug.c:21: internal compiler error: in ?, at recog.c:2083 Please submit a full bug report, with preprocessed source if appropriate. See <URL:http://www.intrepid.com/upc/bugs.html> for instructions. ----- alpha.c/md code that produces RTL in question ----- The following call to get_unaligned_address returns (plus:DI (reg/f:DI 71) (const_int 6 [0x6])) which is passed as the first argument of the gen_unaligned_storehi() 2929 /* Expand a non-bwx QImode or HImode move instruction; 2930 return true if all work is done. */ 2931 2932 bool 2933 alpha_expand_mov_nobwx (enum machine_mode mode, rtx *operands) 2934 { ... 3040 rtx temp1 = gen_reg_rtx (DImode); 3041 rtx temp2 = gen_reg_rtx (DImode); 3042 rtx temp3 = gen_reg_rtx (DImode); 3043 rtx seq = ((mode == QImode 3044 ? gen_unaligned_storeqi 3045 : gen_unaligned_storehi) 3046 (get_unaligned_address (operands[0], 0), 3047 operands[1], temp1, temp2, temp3)); 3048 3049 alpha_set_memflags (seq, operands[0]); 3050 emit_insn (seq); 3051 } Later on, gen_unaligned_storehi() creates the offending unrecognizable INSN with the following code: (define_expand "unaligned_storehi_be" [(set (match_operand:DI 3 "register_operand" "") (mem:DI (and:DI (match_operand:DI 0 "address_operand" "") (const_int -8)))) (set (match_operand:DI 2 "register_operand" "") (plus:DI (match_dup 0) (const_int 1))) <<<<<<<<======= (set (match_dup 3) (and:DI (not:DI (ashift:DI (const_int 65535) (minus:DI (const_int 56) (ashift:DI (match_dup 2) (const_int 3))))) (match_dup 3))) (set (match_operand:DI 4 "register_operand" "") (ashift:DI (zero_extend:DI (match_operand:HI 1 "register_operand" "")) (minus:DI (const_int 56) (ashift:DI (match_dup 2) (const_int 3))))) (set (match_dup 4) (ior:DI (match_dup 4) (match_dup 3))) (set (mem:DI (and:DI (match_dup 0) (const_int -8))) (match_dup 4))] "WORDS_BIG_ENDIAN" "") If I change line 3043 in alpha.c to load unaligned address of operand[0] into the register and pass it to unaligned_storehi() everything works. ----- RTL dump 01.rtl ----- ;; Function main (note 2 0 3 NOTE_INSN_DELETED) (note 3 2 4 NOTE_INSN_FUNCTION_BEG) (note 4 3 5 NOTE_INSN_DELETED) (insn 5 4 6 (set (reg:DI 70) (symbol_ref:DI ("__main") [flags 0x41])) -1 (nil) (nil)) (insn 6 5 7 (set (reg:DI 25 $25) (unspec:DI [ (const_int 0 [0x0]) ] 9)) -1 (nil) (nil)) (call_insn 7 6 8 (parallel [ (call (mem:DI (reg:DI 70) [0 S8 A64]) (unspec:DI [ (const_int 0 [0x0]) ] 9)) (use (reg:DI 25 $25)) (clobber (reg:DI 26 $26)) ]) -1 (nil) (expr_list:REG_EH_REGION (const_int 0 [0x0]) (nil)) (nil)) (note 8 7 9 40007161440 NOTE_INSN_BLOCK_BEG) (note 9 8 11 NOTE_INSN_DELETED) (insn 11 9 12 (set (reg/f:DI 71) (symbol_ref:DI ("x") [flags 0x2] <var_decl 40014626060 x>)) -1 (nil) (nil)) (insn 12 11 13 (set (reg:HI 72) (const_int 2 [0x2])) -1 (nil) (nil)) (insn 13 12 14 (set (reg:DI 74) (mem/s:DI (and:DI (plus:DI (reg/f:DI 71) (const_int 6 [0x6])) (const_int -8 [0xfffffffffffffff8])) [0 S8 A64])) -1 (nil) (nil)) (insn 14 13 15 (set (reg:DI 73) (plus:DI (plus:DI (reg/f:DI 71) (const_int 6 [0x6])) (const_int 1 [0x1]))) -1 (nil) (nil)) (insn 15 14 16 (set (reg:DI 74) (and:DI (not:DI (ashift:DI (const_int 65535 [0xffff]) (minus:DI (const_int 56 [0x38]) (ashift:DI (reg:DI 73) (const_int 3 [0x3]))))) (reg:DI 74))) -1 (nil) (nil)) (insn 16 15 17 (set (reg:DI 75) (ashift:DI (zero_extend:DI (reg:HI 72)) (minus:DI (const_int 56 [0x38]) (ashift:DI (reg:DI 73) (const_int 3 [0x3]))))) -1 (nil) (nil)) (insn 17 16 18 (set (reg:DI 75) (ior:DI (reg:DI 75) (reg:DI 74))) -1 (nil) (nil)) (insn 18 17 19 (set (mem:DI (and:DI (plus:DI (reg/f:DI 71) (const_int 6 [0x6])) (const_int -8 [0xfffffffffffffff8])) [0 S8 A64]) (reg:DI 75)) -1 (nil) (nil)) (note 19 18 20 40007161440 NOTE_INSN_BLOCK_END) (note 20 19 24 NOTE_INSN_FUNCTION_END) (insn 24 20 25 (clobber (reg/i:DI 0 $0)) -1 (nil) (nil)) (insn 25 24 22 (clobber (reg:DI 69 [ <result> ])) -1 (nil) (nil)) (code_label 22 25 23 1 "" [0 uses]) (insn 23 22 26 (set (reg/i:DI 0 $0) (reg:DI 69 [ <result> ])) -1 (nil) (nil)) (insn 26 23 0 (use (reg/i:DI 0 $0)) -1 (nil) (nil)) -- Summary: Unaligned access to HI values causes unrecognizable insn error Product: gcc Version: 3.4.5 Status: UNCONFIRMED Severity: critical Priority: P2 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: nenad at intrepid dot com CC: gcc-bugs at gcc dot gnu dot org GCC build triplet: alphaev5-cray-unicosmk2.0.6.X GCC host triplet: alphaev5-cray-unicosmk2.0.6.X GCC target triplet: alphaev5-cray-unicosmk2.0.6.X http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22093