From 2da1e7c02214850d6b49a1f63c29fe6ccb7118a9 Mon Sep 17 00:00:00 2001 From: Chung-Ju Wu Date: Wed, 3 Sep 2014 09:04:46 +0000 Subject: [PATCH] [NDS32] We need to make sure it is NOT a variadic function so that some v3push/v3pop preparation can be applied. -- The rationale of such avoidance is that the 'pop25' instruction also contains return behavior and we have no chance to further adjust stack pointer before returning to caller, which is very important to variadic function. -- So we do not setup v3push/v3pop (push25/pop25) information for a variadic function. It will use normal stack push/pop instead. * config/nds32/nds32.c (nds32_compute_stack_frame): Do not use v3push/v3pop for variadic function. * config/nds32/nds32.md (prologue, epilogue): Likewise. From-SVN: r214857 --- gcc/ChangeLog | 6 ++++++ gcc/config/nds32/nds32.c | 17 ++++++++++++----- gcc/config/nds32/nds32.md | 16 ++++++++++++---- 3 files changed, 30 insertions(+), 9 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a8d27bf6ac1..7d871025608 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2014-09-03 Chung-Ju Wu + + * config/nds32/nds32.c (nds32_compute_stack_frame): Do not use + v3push/v3pop for variadic function. + * config/nds32/nds32.md (prologue, epilogue): Likewise. + 2014-09-03 Chung-Ju Wu * config/nds32/nds32-md-auxiliary.c (nds32_output_stack_push): diff --git a/gcc/config/nds32/nds32.c b/gcc/config/nds32/nds32.c index da3087fd85a..f54d700f085 100644 --- a/gcc/config/nds32/nds32.c +++ b/gcc/config/nds32/nds32.c @@ -215,7 +215,8 @@ nds32_compute_stack_frame (void) which means we do not have to save any callee-saved registers. condition 2: Both $lp and $fp are NOT live in this function, - which means we do not need to save them. + which means we do not need to save them and there + is no outgoing size. condition 3: There is no local_size, which means we do not need to adjust $sp. */ if (lookup_attribute ("naked", DECL_ATTRIBUTES (current_function_decl)) @@ -225,8 +226,11 @@ nds32_compute_stack_frame (void) && !df_regs_ever_live_p (LP_REGNUM) && cfun->machine->local_size == 0)) { - /* Set this function 'naked_p' and - other functions can check this flag. */ + /* Set this function 'naked_p' and other functions can check this flag. + Note that in nds32 port, the 'naked_p = 1' JUST means there is no + callee-saved, local size, and outgoing size. + The varargs space and ret instruction may still present in + the prologue/epilogue expanding. */ cfun->machine->naked_p = 1; /* No need to save $fp, $gp, and $lp. @@ -250,8 +254,11 @@ nds32_compute_stack_frame (void) we need to make sure Rb is $r6 and Re is located on $r6, $r8, $r10, or $r14. Some results above will be discarded and recomputed. - Note that it is only available under V3/V3M ISA. */ - if (TARGET_V3PUSH) + Note that it is only available under V3/V3M ISA and we + DO NOT setup following stuff for isr or variadic function. */ + if (TARGET_V3PUSH + && !nds32_isr_function_p (current_function_decl) + && (cfun->machine->va_args_size == 0)) { /* Recompute: cfun->machine->fp_size diff --git a/gcc/config/nds32/nds32.md b/gcc/config/nds32/nds32.md index ccf33d9861e..18d6d1b52ef 100644 --- a/gcc/config/nds32/nds32.md +++ b/gcc/config/nds32/nds32.md @@ -1971,8 +1971,12 @@ create_template: (define_expand "prologue" [(const_int 0)] "" { - /* Note that only under V3/V3M ISA, we could use v3push prologue. */ - if (TARGET_V3PUSH) + /* Note that only under V3/V3M ISA, we could use v3push prologue. + In addition, we do not want to use v3push for isr function + and variadic function. */ + if (TARGET_V3PUSH + && !nds32_isr_function_p (current_function_decl) + && (cfun->machine->va_args_size == 0)) nds32_expand_prologue_v3push (); else nds32_expand_prologue (); @@ -1982,8 +1986,12 @@ create_template: (define_expand "epilogue" [(const_int 0)] "" { - /* Note that only under V3/V3M ISA, we could use v3pop epilogue. */ - if (TARGET_V3PUSH) + /* Note that only under V3/V3M ISA, we could use v3pop epilogue. + In addition, we do not want to use v3pop for isr function + and variadic function. */ + if (TARGET_V3PUSH + && !nds32_isr_function_p (current_function_decl) + && (cfun->machine->va_args_size == 0)) nds32_expand_epilogue_v3pop (); else nds32_expand_epilogue (); -- 2.30.2