TCG: remove broken stack allocation for call arguments

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>

diff --git a/tcg/tcg.c b/tcg/tcg.c
index d8bf72159f039847309cff90f8dda0a1db6093df..29cd7a27290f649c3c6bacbffc4c4f380be12aa1 100644 (file)
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -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++) {