[Guile-commits] 19/20: Stack alignment takes saved return address into account

[Andy Wingo]

wingo pushed a commit to branch lightening
in repository guile.

commit 04cd8874de9713e53e9e0cfe5c0195bd356ebe8e
Author: Andy Wingo <address@hidden>
Date:   Sun Apr 28 12:36:16 2019 +0200

    Stack alignment takes saved return address into account
---
 lightening/lightening.c | 16 ++++++----------
 lightening/x86.c        | 12 +++++++-----
 tests/jmpr.c            |  2 ++
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/lightening/lightening.c b/lightening/lightening.c
index d18aa83..8426672 100644
--- a/lightening/lightening.c
+++ b/lightening/lightening.c
@@ -68,12 +68,6 @@ struct jit_state
 # define UNLIKELY(exprn) exprn
 #endif
 
-enum stack_state
-{
-  BEFORE_CALL,
-  AFTER_CALL
-};
-
 static jit_bool_t jit_get_cpu(void);
 static jit_bool_t jit_init(jit_state_t *);
 static void jit_flush(void *fptr, void *tptr);
@@ -83,8 +77,7 @@ static void jit_try_shorten(jit_state_t *_jit, jit_reloc_t 
reloc,
 struct abi_arg_iterator;
 
 static void reset_abi_arg_iterator(struct abi_arg_iterator *iter, size_t argc,
-                                   const jit_operand_t *args,
-                                   enum stack_state state);
+                                   const jit_operand_t *args);
 static void next_abi_arg(struct abi_arg_iterator *iter,
                          jit_operand_t *arg);
 
@@ -931,6 +924,9 @@ jit_enter_jit_abi(jit_state_t *_jit, size_t v, size_t vf, 
size_t frame_size)
   ASSERT(v <= v_count);
   ASSERT(vf <= vf_count);
 
+  ASSERT(_jit->frame_size == 0);
+  _jit->frame_size = jit_initial_frame_size();
+
   /* Save values of callee-save registers.  */
   for (size_t i = 0; i < v; i++)
     jit_pushr (_jit, V[i]);
@@ -969,7 +965,7 @@ prepare_call_args(jit_state_t *_jit, size_t argc, 
jit_operand_t args[])
   struct abi_arg_iterator iter;
   
   // Compute shuffle destinations and space for spilled arguments.
-  reset_abi_arg_iterator(&iter, argc, args, BEFORE_CALL);
+  reset_abi_arg_iterator(&iter, argc, args);
   for (size_t i = 0; i < argc; i++)
     next_abi_arg(&iter, &dst[i]);
 
@@ -1022,7 +1018,7 @@ jit_locate_args(jit_state_t *_jit, size_t argc, 
jit_operand_t args[])
 {
   struct abi_arg_iterator iter;
     
-  reset_abi_arg_iterator(&iter, argc, args, AFTER_CALL);
+  reset_abi_arg_iterator(&iter, argc, args);
   iter.stack_size += _jit->frame_size;
   for (size_t i = 0; i < argc; i++)
     next_abi_arg(&iter, &args[i]);
diff --git a/lightening/x86.c b/lightening/x86.c
index c14133c..bf48c18 100644
--- a/lightening/x86.c
+++ b/lightening/x86.c
@@ -315,17 +315,19 @@ round_size_up_to_words(size_t bytes)
   return words * word_size;
 }
 
+static size_t
+jit_initial_frame_size (void)
+{
+  return __WORDSIZE / 8; // Saved return address is on stack.
+}
+
 static void
 reset_abi_arg_iterator(struct abi_arg_iterator *iter, size_t argc,
-                       const jit_operand_t *args, enum stack_state state)
+                       const jit_operand_t *args)
 {
   memset(iter, 0, sizeof *iter);
   iter->argc = argc;
   iter->args = args;
-  if (state == AFTER_CALL)
-    iter->stack_size = __WORDSIZE / 8; // Saved return address.
-  else
-    ASSERT(state == BEFORE_CALL);
 }
 
 static void
diff --git a/tests/jmpr.c b/tests/jmpr.c
index e81a027..8840897 100644
--- a/tests/jmpr.c
+++ b/tests/jmpr.c
@@ -6,7 +6,9 @@ static void
 run_test(jit_state_t *j, uint8_t *arena_base, size_t arena_size)
 {
   jit_begin(j, arena_base, arena_size);
+  size_t align = jit_enter_jit_abi(j, 0, 0, 0);
   jit_load_args_1(j, jit_operand_gpr (JIT_OPERAND_ABI_POINTER, JIT_R0));
+  jit_leave_jit_abi(j, 0, 0, align);
 
   jit_jmpr(j, JIT_R0);