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TCG: remove broken stack allocation for call arguments

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The code for stack allocation for call arguments is way too simplistic
to actually work on targets with non-trivial stack allocation policies,
e.g. ppc64. We've also already allocated TCG_STATIC_CALL_ARGS_SIZE worth
of stack for calls which should be well more than any helper needs.

Remove broken dynamic stack allocation code and replace it with an assert.
Should dynamic stack allocation ever be needed again, target specific
functions should be added.

Thanks to Richard Henderson for the analysis.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Blue Swirl 2011-05-28 07:13:05 +00:00
parent b591dc59bc
commit 345649c054
1 changed files with 3 additions and 6 deletions
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9
tcg/tcg.c
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@ -1845,13 +1845,14 @@ static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
nb_regs = nb_params;
/* assign stack slots first */
/* XXX: preallocate call stack */
call_stack_size = (nb_params - nb_regs) * sizeof(tcg_target_long);
call_stack_size = (call_stack_size + TCG_TARGET_STACK_ALIGN - 1) &
~(TCG_TARGET_STACK_ALIGN - 1);
allocate_args = (call_stack_size > TCG_STATIC_CALL_ARGS_SIZE);
if (allocate_args) {
tcg_out_addi(s, TCG_REG_CALL_STACK, -STACK_DIR(call_stack_size));
/* XXX: if more than TCG_STATIC_CALL_ARGS_SIZE is needed,
preallocate call stack */
tcg_abort();
}
stack_offset = TCG_TARGET_CALL_STACK_OFFSET;
@ -1970,10 +1971,6 @@ static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
}
tcg_out_op(s, opc, &func_arg, &const_func_arg);
if (allocate_args) {
tcg_out_addi(s, TCG_REG_CALL_STACK, STACK_DIR(call_stack_size));
}
/* assign output registers and emit moves if needed */
for(i = 0; i < nb_oargs; i++) {