| Summary: | Incomplete check in RTL for "pm()" annotation | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Wouter van Gulik <wvangulik> |
| Component: | target | Assignee: | Not yet assigned to anyone <unassigned> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | andrewhutchinson, eric.weddington, gcc-bugs |
| Priority: | P3 | ||
| Version: | 4.2.2 | ||
| Target Milestone: | 4.5.0 | ||
| Host: | Target: | avr-*-* | |
| Build: | Known to work: | ||
| Known to fail: | Last reconfirmed: | 2008-04-03 22:28:59 | |
| Attachments: | Patch | ||
Created attachment 15169 [details] Patch The attached patch allows function address expressions of the form address+k to be correctly recognized as program memory addresses and thus force use of pm() assembler syntax. This has not been extensively tested but assembler appears to be correct for this bugs testcase and a similar issue found in: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27192 Note, odd addresses will be accepted by C and only cause linker warning. Subject: Bug 35013 Author: hutchinsonandy Date: Thu Dec 24 19:53:57 2009 New Revision: 155459 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155459 Log: 2009-12-24 Andy Hutchinson <hutchinsonandy@gcc.gnu.org> PR target/35013, 27192 * config/avr/avr.c (print_operand_address): Print correct program memory address. Add warning for large device offset addresses. (avr_assemble_integer): Ditto. (print_operand): Add warnings for incorrect addressing. (out_movqi_r_mr): Tag assembler with new address codes. (out_movhi_r_mr): Ditto. (out_movsi_r_mr): Ditto. (out_movqi_mr_r): Ditto. (out_movhi_mr_r): Ditto. (out_movsi_mr_r): Ditto. * config/avr/predicates.md (text_segment_operand): New predicate. * config/avr/avr.md (jump): Tag assembler with new address codes. (call_insn): Ditto. (call_value_insn): Ditto. (*tablejump_lib): Ditto. (*cbi): Ditto. (*sbi): Ditto. (indirect_jump): New define_expand. (jcindirect_jump): New pattern for constant expression jump. (njcindirect_jump): Renamed old indirect_jump. Modified: trunk/gcc/ChangeLog trunk/gcc/config/avr/avr.c trunk/gcc/config/avr/avr.md trunk/gcc/config/avr/predicates.md Fixed 4.5 |
All credits for finding the root of the evil go to Andrew Hutchinson His original e-mail: There is a bug! Backend (avr part) creates special "pm()" annotation by looking at RTL. This is done in avr.c by this function: static bool avr_assemble_integer (rtx x, unsigned int size, int aligned_p) { debug_rtx(x); /*ADDED TO DEBUG*/ fprintf(stderr,"size=%d align=%d\n\n",size,aligned_p); /*ADDED TO DEBUG*/ if (size == POINTER_SIZE / BITS_PER_UNIT && aligned_p && ((GET_CODE (x) == SYMBOL_REF && SYMBOL_REF_FUNCTION_P (x)) || GET_CODE (x) == LABEL_REF)) { fputs ("\t.word\tpm(", asm_out_file); output_addr_const (asm_out_file, x); fputs (")\n", asm_out_file); return true; } return default_assemble_integer (x, size, aligned_p); } (I added 2 lines to debug it) You will see it looks symbol_ref or label_ref - otherwise it does not use pm. So I ran it with following testcase to see what argument get sent: //Dummy func int table[]= {1,2}; char ctable[]= {3,4}; void foo(void) {} //Table with address manipulation void (* const pFuncTable[]) (void) = { foo + 0, (foo + 1), foo +2 }; ....and we get the following: (const_int 1 [0x1]) size=2 align=1 (const_int 2 [0x2]) size=2 align=1 (const_int 3 [0x3]) size=1 align=1 (const_int 4 [0x4]) size=1 align=1 (symbol_ref:HI ("foo") [flags 0x3] <function_decl 0x7fdcf030 foo>) size=2 align=1 (const:HI (plus:HI (symbol_ref:HI ("foo") [flags 0x3] <function_decl 0x7fdcf030 foo>) (const_int 1 [0x1]))) size=2 align=1 (const:HI (plus:HI (symbol_ref:HI ("foo") [flags 0x3] <function_decl 0x7fdcf030 foo>) (const_int 2 [0x2]))) size=2 align=1 You will see last two cases are an expression with outer code as const:HI so it will not match, it does not add pm().