From 3eda5123a4985b89bb748d98258f63f9e343c294 Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Thu, 9 Aug 2012 17:02:36 +0200 Subject: [PATCH] alpha.c (alpha_pad_noreturn): Rename to ... * config/alpha/alpha.c (alpha_pad_noreturn): Rename to ... (alpha_pad_function_end): ... this. Also insert NOP between sibling call and GP load. (alpha_reorg): Update call to alpha_pad_function_end. Expand comment. From-SVN: r190255 --- gcc/ChangeLog | 9 ++++++++- gcc/config/alpha/alpha.c | 35 ++++++++++++++++++++++++++++------- 2 files changed, 36 insertions(+), 8 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index db6dbd5..c3392e9 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2012-08-09 Uros Bizjak + + * config/alpha/alpha.c (alpha_pad_noreturn): Rename to ... + (alpha_pad_function_end): ... this. Also insert NOP between + sibling call and GP load. + (alpha_reorg): Update call to alpha_pad_function_end. Expand comment. + 2012-08-09 Michael Zolotukhin * config/i386/adxintrin.h: Remove guarding __ADX__ check. @@ -14,7 +21,7 @@ * sel-sched.c (vinsn_vec_has_expr_p): Clarify function comment. Process not only expr's vinsns but all old vinsns from expr's history of changes. - (update_and_record_unavailable_insns): Clarify comment. + (update_and_record_unavailable_insns): Clarify comment. 2012-08-09 Bernd Schmidt diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c index 6d455ef..2d6ba95 100644 --- a/gcc/config/alpha/alpha.c +++ b/gcc/config/alpha/alpha.c @@ -9258,17 +9258,18 @@ alpha_align_insns (unsigned int max_align, } } -/* Insert an unop between a noreturn function call and GP load. */ +/* Insert an unop between sibcall or noreturn function call and GP load. */ static void -alpha_pad_noreturn (void) +alpha_pad_function_end (void) { rtx insn, next; for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) { if (! (CALL_P (insn) - && find_reg_note (insn, REG_NORETURN, NULL_RTX))) + && (SIBLING_CALL_P (insn) + || find_reg_note (insn, REG_NORETURN, NULL_RTX)))) continue; /* Make sure we do not split a call and its corresponding @@ -9300,8 +9301,28 @@ alpha_pad_noreturn (void) static void alpha_reorg (void) { - /* Workaround for a linker error that triggers when an - exception handler immediatelly follows a noreturn function. + /* Workaround for a linker error that triggers when an exception + handler immediatelly follows a sibcall or a noreturn function. + +In the sibcall case: + + The instruction stream from an object file: + + 1d8: 00 00 fb 6b jmp (t12) + 1dc: 00 00 ba 27 ldah gp,0(ra) + 1e0: 00 00 bd 23 lda gp,0(gp) + 1e4: 00 00 7d a7 ldq t12,0(gp) + 1e8: 00 40 5b 6b jsr ra,(t12),1ec <__funcZ+0x1ec> + + was converted in the final link pass to: + + 12003aa88: 67 fa ff c3 br 120039428 <...> + 12003aa8c: 00 00 fe 2f unop + 12003aa90: 00 00 fe 2f unop + 12003aa94: 48 83 7d a7 ldq t12,-31928(gp) + 12003aa98: 00 40 5b 6b jsr ra,(t12),12003aa9c <__func+0x1ec> + +And in the noreturn case: The instruction stream from an object file: @@ -9321,11 +9342,11 @@ alpha_reorg (void) GP load instructions were wrongly cleared by the linker relaxation pass. This workaround prevents removal of GP loads by inserting - an unop instruction between a noreturn function call and + an unop instruction between a sibcall or noreturn function call and exception handler prologue. */ if (current_function_has_exception_handlers ()) - alpha_pad_noreturn (); + alpha_pad_function_end (); if (alpha_tp != ALPHA_TP_PROG || flag_exceptions) alpha_handle_trap_shadows (); -- 2.7.4