/* Emit RTL for the GCC expander.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
This file is part of GCC.
static reg_attrs *get_reg_attrs (tree, int);
static tree component_ref_for_mem_expr (tree);
static rtx gen_const_vector (enum machine_mode, int);
-static rtx gen_complex_constant_part (enum machine_mode, rtx, int);
static void copy_rtx_if_shared_1 (rtx *orig);
/* Probability of the conditional branch currently proceeded by try_split.
return mem;
}
-rtx
-gen_rtx_SUBREG (enum machine_mode mode, rtx reg, int offset)
+/* We want to create (subreg:OMODE (obj:IMODE) OFFSET). Return true if
+ this construct would be valid, and false otherwise. */
+
+bool
+validate_subreg (enum machine_mode omode, enum machine_mode imode,
+ rtx reg, unsigned int offset)
{
- /* This is the most common failure type.
- Catch it early so we can see who does it. */
- gcc_assert (!(offset % GET_MODE_SIZE (mode)));
+ unsigned int isize = GET_MODE_SIZE (imode);
+ unsigned int osize = GET_MODE_SIZE (omode);
- /* This check isn't usable right now because combine will
- throw arbitrary crap like a CALL into a SUBREG in
- gen_lowpart_for_combine so we must just eat it. */
-#if 0
- /* Check for this too. */
- gcc_assert (offset < GET_MODE_SIZE (GET_MODE (reg)));
+ /* All subregs must be aligned. */
+ if (offset % osize != 0)
+ return false;
+
+ /* The subreg offset cannot be outside the inner object. */
+ if (offset >= isize)
+ return false;
+
+ /* ??? This should not be here. Temporarily continue to allow word_mode
+ subregs of anything. The most common offender is (subreg:SI (reg:DF)).
+ Generally, backends are doing something sketchy but it'll take time to
+ fix them all. */
+ if (omode == word_mode)
+ ;
+ /* ??? Similarly, e.g. with (subreg:DF (reg:TI)). Though store_bit_field
+ is the culprit here, and not the backends. */
+ else if (osize >= UNITS_PER_WORD && isize >= osize)
+ ;
+ /* Allow component subregs of complex and vector. Though given the below
+ extraction rules, it's not always clear what that means. */
+ else if ((COMPLEX_MODE_P (imode) || VECTOR_MODE_P (imode))
+ && GET_MODE_INNER (imode) == omode)
+ ;
+ /* ??? x86 sse code makes heavy use of *paradoxical* vector subregs,
+ i.e. (subreg:V4SF (reg:SF) 0). This surely isn't the cleanest way to
+ represent this. It's questionable if this ought to be represented at
+ all -- why can't this all be hidden in post-reload splitters that make
+ arbitrarily mode changes to the registers themselves. */
+ else if (VECTOR_MODE_P (omode) && GET_MODE_INNER (omode) == imode)
+ ;
+ /* Subregs involving floating point modes are not allowed to
+ change size. Therefore (subreg:DI (reg:DF) 0) is fine, but
+ (subreg:SI (reg:DF) 0) isn't. */
+ else if (FLOAT_MODE_P (imode) || FLOAT_MODE_P (omode))
+ {
+ if (isize != osize)
+ return false;
+ }
+
+ /* Paradoxical subregs must have offset zero. */
+ if (osize > isize)
+ return offset == 0;
+
+ /* This is a normal subreg. Verify that the offset is representable. */
+
+ /* For hard registers, we already have most of these rules collected in
+ subreg_offset_representable_p. */
+ if (reg && REG_P (reg) && HARD_REGISTER_P (reg))
+ {
+ unsigned int regno = REGNO (reg);
+
+#ifdef CANNOT_CHANGE_MODE_CLASS
+ if ((COMPLEX_MODE_P (imode) || VECTOR_MODE_P (imode))
+ && GET_MODE_INNER (imode) == omode)
+ ;
+ else if (REG_CANNOT_CHANGE_MODE_P (regno, imode, omode))
+ return false;
#endif
+
+ return subreg_offset_representable_p (regno, imode, offset, omode);
+ }
+
+ /* For pseudo registers, we want most of the same checks. Namely:
+ If the register no larger than a word, the subreg must be lowpart.
+ If the register is larger than a word, the subreg must be the lowpart
+ of a subword. A subreg does *not* perform arbitrary bit extraction.
+ Given that we've already checked mode/offset alignment, we only have
+ to check subword subregs here. */
+ if (osize < UNITS_PER_WORD)
+ {
+ enum machine_mode wmode = isize > UNITS_PER_WORD ? word_mode : imode;
+ unsigned int low_off = subreg_lowpart_offset (omode, wmode);
+ if (offset % UNITS_PER_WORD != low_off)
+ return false;
+ }
+ return true;
+}
+
+rtx
+gen_rtx_SUBREG (enum machine_mode mode, rtx reg, int offset)
+{
+ gcc_assert (validate_subreg (mode, GET_MODE (reg), reg, offset));
return gen_rtx_raw_SUBREG (mode, reg, offset);
}
return 0;
}
\f
-/* Return the constant real or imaginary part (which has mode MODE)
- of a complex value X. The IMAGPART_P argument determines whether
- the real or complex component should be returned. This function
- returns NULL_RTX if the component isn't a constant. */
-
-static rtx
-gen_complex_constant_part (enum machine_mode mode, rtx x, int imagpart_p)
-{
- tree decl, part;
-
- if (MEM_P (x)
- && GET_CODE (XEXP (x, 0)) == SYMBOL_REF)
- {
- decl = SYMBOL_REF_DECL (XEXP (x, 0));
- if (decl != NULL_TREE && TREE_CODE (decl) == COMPLEX_CST)
- {
- part = imagpart_p ? TREE_IMAGPART (decl) : TREE_REALPART (decl);
- if (TREE_CODE (part) == REAL_CST
- || TREE_CODE (part) == INTEGER_CST)
- return expand_expr (part, NULL_RTX, mode, 0);
- }
- }
- return NULL_RTX;
-}
-
-/* Return the real part (which has mode MODE) of a complex value X.
- This always comes at the low address in memory. */
-
-rtx
-gen_realpart (enum machine_mode mode, rtx x)
-{
- rtx part;
-
- /* Handle complex constants. */
- part = gen_complex_constant_part (mode, x, 0);
- if (part != NULL_RTX)
- return part;
-
- if (WORDS_BIG_ENDIAN
- && GET_MODE_BITSIZE (mode) < BITS_PER_WORD
- && REG_P (x)
- && REGNO (x) < FIRST_PSEUDO_REGISTER)
- internal_error
- ("can't access real part of complex value in hard register");
- else if (WORDS_BIG_ENDIAN)
- return gen_highpart (mode, x);
- else
- return gen_lowpart (mode, x);
-}
-
-/* Return the imaginary part (which has mode MODE) of a complex value X.
- This always comes at the high address in memory. */
-
-rtx
-gen_imagpart (enum machine_mode mode, rtx x)
-{
- rtx part;
-
- /* Handle complex constants. */
- part = gen_complex_constant_part (mode, x, 1);
- if (part != NULL_RTX)
- return part;
-
- if (WORDS_BIG_ENDIAN)
- return gen_lowpart (mode, x);
- else if (! WORDS_BIG_ENDIAN
- && GET_MODE_BITSIZE (mode) < BITS_PER_WORD
- && REG_P (x)
- && REGNO (x) < FIRST_PSEUDO_REGISTER)
- internal_error
- ("can't access imaginary part of complex value in hard register");
- else
- return gen_highpart (mode, x);
-}
-\f
rtx
gen_highpart (enum machine_mode mode, rtx x)
{
if (base && DECL_P (base)
&& TREE_READONLY (base)
&& (TREE_STATIC (base) || DECL_EXTERNAL (base)))
- MEM_READONLY_P (ref) = 1;
+ {
+ tree base_type = TREE_TYPE (base);
+ gcc_assert (!(base_type && TYPE_NEEDS_CONSTRUCTING (base_type))
+ || DECL_ARTIFICIAL (base));
+ MEM_READONLY_P (ref) = 1;
+ }
if (TREE_THIS_VOLATILE (t))
MEM_VOLATILE_P (ref) = 1;
|| TREE_CODE (t) == SAVE_EXPR)
t = TREE_OPERAND (t, 0);
- /* If this expression can't be addressed (e.g., it contains a reference
- to a non-addressable field), show we don't change its alias set. */
- if (! can_address_p (t))
+ /* If this expression uses it's parent's alias set, mark it such
+ that we won't change it. */
+ if (component_uses_parent_alias_set (t))
MEM_KEEP_ALIAS_SET_P (ref) = 1;
/* If this is a decl, set the attributes of the MEM from it. */
rtx
get_first_nonnote_insn (void)
{
- rtx insn;
+ rtx insn = first_insn;
+
+ if (insn)
+ {
+ if (NOTE_P (insn))
+ for (insn = next_insn (insn);
+ insn && NOTE_P (insn);
+ insn = next_insn (insn))
+ continue;
+ else
+ {
+ if (GET_CODE (insn) == INSN
+ && GET_CODE (PATTERN (insn)) == SEQUENCE)
+ insn = XVECEXP (PATTERN (insn), 0, 0);
+ }
+ }
- for (insn = first_insn; insn && NOTE_P (insn); insn = next_insn (insn));
return insn;
}
rtx
get_last_nonnote_insn (void)
{
- rtx insn;
+ rtx insn = last_insn;
+
+ if (insn)
+ {
+ if (NOTE_P (insn))
+ for (insn = previous_insn (insn);
+ insn && NOTE_P (insn);
+ insn = previous_insn (insn))
+ continue;
+ else
+ {
+ if (GET_CODE (insn) == INSN
+ && GET_CODE (PATTERN (insn)) == SEQUENCE)
+ insn = XVECEXP (PATTERN (insn), 0,
+ XVECLEN (PATTERN (insn), 0) - 1);
+ }
+ }
- for (insn = last_insn; insn && NOTE_P (insn); insn = previous_insn (insn));
return insn;
}
case REG_NORETURN:
case REG_SETJMP:
- case REG_ALWAYS_RETURN:
insn = insn_last;
while (insn != NULL_RTX)
{
if (INSN_P (insn))
bb->flags |= BB_DIRTY;
/* Should not happen as first in the BB is always either NOTE or
- LABEl. */
+ LABEL. */
gcc_assert (BB_HEAD (bb) != insn
/* Avoid clobbering of structure when creating new BB. */
|| BARRIER_P (insn)
void
remove_unnecessary_notes (void)
{
- rtx block_stack = NULL_RTX;
rtx eh_stack = NULL_RTX;
rtx insn;
rtx next;
break;
case NOTE_INSN_BLOCK_BEG:
- /* By now, all notes indicating lexical blocks should have
- NOTE_BLOCK filled in. */
- gcc_assert (NOTE_BLOCK (insn));
- block_stack = alloc_INSN_LIST (insn, block_stack);
- break;
-
case NOTE_INSN_BLOCK_END:
- /* Too many end notes. */
- gcc_assert (block_stack);
- /* Mismatched nesting. */
- gcc_assert (NOTE_BLOCK (XEXP (block_stack, 0)) == NOTE_BLOCK (insn));
- tmp = block_stack;
- block_stack = XEXP (block_stack, 1);
- free_INSN_LIST_node (tmp);
+ /* BLOCK_END and BLOCK_BEG notes only exist in the `final' pass. */
+ gcc_unreachable ();
- /* Scan back to see if there are any non-note instructions
- between INSN and the beginning of this block. If not,
- then there is no PC range in the generated code that will
- actually be in this block, so there's no point in
- remembering the existence of the block. */
- for (tmp = PREV_INSN (insn); tmp; tmp = PREV_INSN (tmp))
- {
- /* This block contains a real instruction. Note that we
- don't include labels; if the only thing in the block
- is a label, then there are still no PC values that
- lie within the block. */
- if (INSN_P (tmp))
- break;
-
- /* We're only interested in NOTEs. */
- if (!NOTE_P (tmp))
- continue;
-
- if (NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BLOCK_BEG)
- {
- /* We just verified that this BLOCK matches us with
- the block_stack check above. Never delete the
- BLOCK for the outermost scope of the function; we
- can refer to names from that scope even if the
- block notes are messed up. */
- if (! is_body_block (NOTE_BLOCK (insn))
- && (*debug_hooks->ignore_block) (NOTE_BLOCK (insn)))
- {
- remove_insn (tmp);
- remove_insn (insn);
- }
- break;
- }
- else if (NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BLOCK_END)
- /* There's a nested block. We need to leave the
- current block in place since otherwise the debugger
- wouldn't be able to show symbols from our block in
- the nested block. */
- break;
- }
+ default:
+ break;
}
}
- /* Too many begin notes. */
- gcc_assert (!block_stack && !eh_stack);
+ /* Too many EH_REGION_BEG notes. */
+ gcc_assert (!eh_stack);
}
\f
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