From 8efaa711904b897f9a4821656ac10f980c5ae9fe Mon Sep 17 00:00:00 2001 From: Thomas Preud'homme Date: Mon, 6 Jan 2014 22:27:39 +0800 Subject: [PATCH] Fix struct ret in variadic fct with ARM hardfloat The procedure calling standard for ARM architecture mandate the use of the base standard for variadic function. Therefore, hgen float aggregate must be returned via stack when greater than 4 bytes and via core registers else in case of variadic function. This patch improve gfunc_sret() to take into account whether the function is variadic or not and make use of gfunc_sret() return value to determine whether to pass a structure via stack in gfunc_prolog(). It also take advantage of knowing if a function is variadic or not move float result value from VFP register to core register in gfunc_epilog(). --- arm-gen.c | 34 ++++++++++++++++++---------------- c67-gen.c | 3 ++- i386-gen.c | 3 ++- il-gen.c | 1 + tcc.h | 3 ++- tccgen.c | 11 ++++++++--- x86_64-gen.c | 3 ++- 7 files changed, 35 insertions(+), 23 deletions(-) diff --git a/arm-gen.c b/arm-gen.c index eecb7d23..9e6c638b 100644 --- a/arm-gen.c +++ b/arm-gen.c @@ -839,12 +839,12 @@ int floats_in_core_regs(SValue *sval) /* Return the number of registers needed to return the struct, or 0 if returning via struct pointer. */ -ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *ret_align) { +ST_FUNC int gfunc_sret(CType *vt, int variadic, CType *ret, int *ret_align) { #ifdef TCC_ARM_EABI int size, align; size = type_size(vt, &align); #ifdef TCC_ARM_HARDFLOAT - if (is_float(vt->t) || is_hgen_float_aggr(vt)) { + if (!variadic && (is_float(vt->t) || is_hgen_float_aggr(vt))) { *ret_align = 8; ret->ref = NULL; ret->t = VT_DOUBLE; @@ -1221,21 +1221,19 @@ void gfunc_call(int nb_args) void gfunc_prolog(CType *func_type) { Sym *sym,*sym2; - int n,nf,size,align, variadic, struct_ret = 0; + int n, nf, size, align, struct_ret = 0; #ifdef TCC_ARM_HARDFLOAT struct avail_regs avregs = AVAIL_REGS_INITIALIZER; #endif + CType ret_type; sym = func_type->ref; func_vt = sym->type; + func_var = (func_type->ref->c == FUNC_ELLIPSIS); n = nf = 0; - variadic = (func_type->ref->c == FUNC_ELLIPSIS); - if((func_vt.t & VT_BTYPE) == VT_STRUCT -#ifdef TCC_ARM_HARDFLOAT - && (variadic || !is_hgen_float_aggr(&func_vt)) -#endif - && type_size(&func_vt,&align) > 4) + if ((func_vt.t & VT_BTYPE) == VT_STRUCT && + !gfunc_sret(&func_vt, func_var, &ret_type, &align)) { n++; struct_ret = 1; @@ -1244,7 +1242,7 @@ void gfunc_prolog(CType *func_type) for(sym2=sym->next;sym2 && (n<4 || nf<16);sym2=sym2->next) { size = type_size(&sym2->type, &align); #ifdef TCC_ARM_HARDFLOAT - if (!variadic && (is_float(sym2->type.t) + if (!func_var && (is_float(sym2->type.t) || is_hgen_float_aggr(&sym2->type))) { int tmpnf = assign_vfpreg(&avregs, align, size); tmpnf += (size + 3) / 4; @@ -1255,9 +1253,9 @@ void gfunc_prolog(CType *func_type) n += (size + 3) / 4; } o(0xE1A0C00D); /* mov ip,sp */ - if(variadic) + if (func_var) n=4; - if(n) { + if (n) { if(n>4) n=4; #ifdef TCC_ARM_EABI @@ -1289,7 +1287,7 @@ void gfunc_prolog(CType *func_type) size = (size + 3) >> 2; align = (align + 3) & ~3; #ifdef TCC_ARM_HARDFLOAT - if (!variadic && (is_float(sym->type.t) + if (!func_var && (is_float(sym->type.t) || is_hgen_float_aggr(&sym->type))) { int fpn = assign_vfpreg(&avregs, align, size << 2); if (fpn >= 0) { @@ -1329,10 +1327,14 @@ void gfunc_epilog(void) { uint32_t x; int diff; + /* Copy float return value to core register if base standard is used and + float computation is made with VFP */ #ifdef TCC_ARM_EABI - /* Useless but harmless copy of the float result into main register(s) in case - of variadic function in the hardfloat variant */ - if(is_float(func_vt.t)) { + if ( +#ifdef TCC_ARM_HARDFLOAT + func_var && +#endif + is_float(func_vt.t)) { if((func_vt.t & VT_BTYPE) == VT_FLOAT) o(0xEE100A10); /* fmrs r0, s0 */ else { diff --git a/c67-gen.c b/c67-gen.c index df4b5d3c..f2baea53 100644 --- a/c67-gen.c +++ b/c67-gen.c @@ -1881,7 +1881,7 @@ static void gcall_or_jmp(int is_jmp) /* Return the number of registers needed to return the struct, or 0 if returning via struct pointer. */ -ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *ret_align) { +ST_FUNC int gfunc_sret(CType *vt, int variadic, CType *ret, int *ret_align) { *ret_align = 1; // Never have to re-align return values for x86-64 return 0; } @@ -1971,6 +1971,7 @@ void gfunc_prolog(CType * func_type) /* if the function returns a structure, then add an implicit pointer parameter */ func_vt = sym->type; + func_var = (sym->c == FUNC_ELLIPSIS); if ((func_vt.t & VT_BTYPE) == VT_STRUCT) { func_vc = addr; addr += 4; diff --git a/i386-gen.c b/i386-gen.c index 4201ac2e..2eb69227 100644 --- a/i386-gen.c +++ b/i386-gen.c @@ -376,7 +376,7 @@ static uint8_t fastcallw_regs[2] = { TREG_ECX, TREG_EDX }; /* Return the number of registers needed to return the struct, or 0 if returning via struct pointer. */ -ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *ret_align) +ST_FUNC int gfunc_sret(CType *vt, int variadic, CType *ret, int *ret_align) { #ifdef TCC_TARGET_PE int size, align; @@ -527,6 +527,7 @@ ST_FUNC void gfunc_prolog(CType *func_type) /* if the function returns a structure, then add an implicit pointer parameter */ func_vt = sym->type; + func_var = (sym->c == FUNC_ELLIPSIS); #ifdef TCC_TARGET_PE size = type_size(&func_vt,&align); if (((func_vt.t & VT_BTYPE) == VT_STRUCT) && (size > 8)) { diff --git a/il-gen.c b/il-gen.c index 33f9f368..9e1ec642 100644 --- a/il-gen.c +++ b/il-gen.c @@ -441,6 +441,7 @@ void gfunc_prolog(int t) /* if the function returns a structure, then add an implicit pointer parameter */ func_vt = sym->t; + func_var = (sym->c == FUNC_ELLIPSIS); if ((func_vt & VT_BTYPE) == VT_STRUCT) { func_vc = addr; addr++; diff --git a/tcc.h b/tcc.h index 50642b78..21957e72 100644 --- a/tcc.h +++ b/tcc.h @@ -1176,6 +1176,7 @@ ST_DATA int const_wanted; /* true if constant wanted */ ST_DATA int nocode_wanted; /* true if no code generation wanted for an expression */ ST_DATA int global_expr; /* true if compound literals must be allocated globally (used during initializers parsing */ ST_DATA CType func_vt; /* current function return type (used by return instruction) */ +ST_DATA int func_var; /* true if current function is variadic */ ST_DATA int func_vc; ST_DATA int last_line_num, last_ind, func_ind; /* debug last line number and pc */ ST_DATA char *funcname; @@ -1288,7 +1289,7 @@ ST_FUNC void gsym_addr(int t, int a); ST_FUNC void gsym(int t); ST_FUNC void load(int r, SValue *sv); ST_FUNC void store(int r, SValue *v); -ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *align); +ST_FUNC int gfunc_sret(CType *vt, int variadic, CType *ret, int *align); ST_FUNC void gfunc_call(int nb_args); ST_FUNC void gfunc_prolog(CType *func_type); ST_FUNC void gfunc_epilog(void); diff --git a/tccgen.c b/tccgen.c index 55b03e69..8355aae0 100644 --- a/tccgen.c +++ b/tccgen.c @@ -66,6 +66,7 @@ ST_DATA int const_wanted; /* true if constant wanted */ ST_DATA int nocode_wanted; /* true if no code generation wanted for an expression */ ST_DATA int global_expr; /* true if compound literals must be allocated globally (used during initializers parsing */ ST_DATA CType func_vt; /* current function return type (used by return instruction) */ +ST_DATA int func_var; /* true if current function is variadic (used by return instruction) */ ST_DATA int func_vc; ST_DATA int last_line_num, last_ind, func_ind; /* debug last line number and pc */ ST_DATA char *funcname; @@ -3960,7 +3961,7 @@ ST_FUNC void unary(void) } else if (tok == '(') { SValue ret; Sym *sa; - int nb_args, ret_nregs, ret_align; + int nb_args, ret_nregs, ret_align, variadic; /* function call */ if ((vtop->type.t & VT_BTYPE) != VT_FUNC) { @@ -3984,7 +3985,9 @@ ST_FUNC void unary(void) ret.r2 = VT_CONST; /* compute first implicit argument if a structure is returned */ if ((s->type.t & VT_BTYPE) == VT_STRUCT) { - ret_nregs = gfunc_sret(&s->type, &ret.type, &ret_align); + variadic = (s->c == FUNC_ELLIPSIS); + ret_nregs = gfunc_sret(&s->type, variadic, &ret.type, + &ret_align); if (!ret_nregs) { /* get some space for the returned structure */ size = type_size(&s->type, &align); @@ -4637,7 +4640,8 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym, if ((func_vt.t & VT_BTYPE) == VT_STRUCT) { CType type, ret_type; int ret_align, ret_nregs; - ret_nregs = gfunc_sret(&func_vt, &ret_type, &ret_align); + ret_nregs = gfunc_sret(&func_vt, func_var, &ret_type, + &ret_align); if (0 == ret_nregs) { /* if returning structure, must copy it to implicit first pointer arg location */ @@ -5747,6 +5751,7 @@ static void gen_function(Sym *sym) cur_text_section = NULL; funcname = ""; /* for safety */ func_vt.t = VT_VOID; /* for safety */ + func_var = 0; /* for safety */ ind = 0; /* for safety */ nocode_wanted = saved_nocode_wanted; } diff --git a/x86_64-gen.c b/x86_64-gen.c index fe028d90..9aee875d 100644 --- a/x86_64-gen.c +++ b/x86_64-gen.c @@ -658,7 +658,7 @@ void gen_offs_sp(int b, int r, int d) /* Return the number of registers needed to return the struct, or 0 if returning via struct pointer. */ -ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *ret_align) +ST_FUNC int gfunc_sret(CType *vt, int variadic, CType *ret, int *ret_align) { int size, align; *ret_align = 1; // Never have to re-align return values for x86-64 @@ -833,6 +833,7 @@ void gfunc_prolog(CType *func_type) /* if the function returns a structure, then add an implicit pointer parameter */ func_vt = sym->type; + func_var = (sym->c == FUNC_ELLIPSIS); size = gfunc_arg_size(&func_vt); if (size > 8) { gen_modrm64(0x89, arg_regs[reg_param_index], VT_LOCAL, NULL, addr); -- 2.11.4.GIT