| Message ID | 4E64995A.5020406@gjlay.de |
|---|---|
| State | New |
| Headers | show |
Index: config/avr/avr.c =================================================================== --- config/avr/avr.c (revision 178525) +++ config/avr/avr.c (working copy) @@ -522,6 +522,17 @@ sequent_regs_live (void) for (reg = 0; reg < 18; ++reg) { + if (fixed_regs[reg]) + { + /* Don't recognize sequences that contain global register + variables. */ + + if (live_seq != 0) + return 0; + else + continue; + } + if (!call_used_regs[reg]) { if (df_regs_ever_live_p (reg))
PR50289 is a minor issue with -mcall-prologues and global register variables resp. fixed registers: Such registers shall be omitted in function prologue/epilogue. For test program void bar (long long, long long, void*); register char x asm ("7"); void foo (char a) { asm volatile ("":::"6"); bar (0, 0, &a); } however, avr.c:sequent_regs_live() generates a register sequence that covers fixed R7, i.e. prologue saves R7...R17, Y and reads foo: ldi r26,lo8(1) ldi r27,hi8(1) ldi r30,lo8(gs(1f)) ldi r31,hi8(gs(1f)) rjmp __prologue_saves__+((18 - 13) * 2) 1: /* prologue: function */ With the patch no sequences are generated that contain fixed regsisters, i.e. prologue for the example reads now foo: push r6 ; 31 pushqi1/1 [length = 1] push r8 ; 32 pushqi1/1 [length = 1] push r9 ; 33 pushqi1/1 [length = 1] push r10 ; 34 pushqi1/1 [length = 1] push r11 ; 35 pushqi1/1 [length = 1] push r12 ; 36 pushqi1/1 [length = 1] push r13 ; 37 pushqi1/1 [length = 1] push r14 ; 38 pushqi1/1 [length = 1] push r15 ; 39 pushqi1/1 [length = 1] push r16 ; 40 pushqi1/1 [length = 1] push r17 ; 41 pushqi1/1 [length = 1] push r28 ; 42 pushqi1/1 [length = 1] push r29 ; 43 pushqi1/1 [length = 1] push __tmp_reg__ ; 47 *addhi3_sp_R_pc2 [length = 1] in r28,__SP_L__ ; 48 *movhi_sp/2 [length = 2] in r29,__SP_H__ /* prologue: function */ Ok to install? Johann PR target/50289 * config/avr/avr.c (sequent_regs_live): Don't recognize sequences that contain global register variable.