Hello!
Attached patch moves remaining non-structural checks from
ix86_decompose_address to ix86_legitimate_address_p. The patch also
introduces ix86_validate_address_register to remove some code
duplication.
2013-11-18 Uros Bizjak <ubiz...@gmail.com>
* config/i386/i386.c (ix86_decompose_address): Use REG_P instead of
ix86_address_subreg_operand. Move subreg checks to
ix86_validate_address_register. Move address override check to
ix86_legitimate_address_p.
(ix86_validate_address_register): New function.
(ix86_legitimate_address_p): Call ix86_validate_address_register
to validate base and index registers. Add address override check
from ix86_decompose_address.
(ix86_decompose_address): Remove.
Tested on x86_64-pc-linux-gnu {,-m32} and committed to mainline SVN.
The patch will be backported to other release branches together with
previous ix86_decompose_address patch [1].
[1] http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01977.html
Uros.
Index: i386.c
===================================================================
--- i386.c (revision 204925)
+++ i386.c (working copy)
@@ -11773,27 +11773,6 @@ ix86_live_on_entry (bitmap regs)
}
}
-/* Determine if op is suitable SUBREG RTX for address. */
-
-static bool
-ix86_address_subreg_operand (rtx op)
-{
- enum machine_mode mode;
-
- if (!REG_P (op))
- return false;
-
- mode = GET_MODE (op);
-
- /* Don't allow SUBREGs that span more than a word. It can lead to spill
- failures when the register is one word out of a two word structure. */
- if (GET_MODE_SIZE (mode) > UNITS_PER_WORD)
- return false;
-
- /* Allow only SUBREGs of non-eliminable hard registers. */
- return register_no_elim_operand (op, mode);
-}
-
/* Extract the parts of an RTL expression that is a valid memory address
for an instruction. Return 0 if the structure of the address is
grossly off. Return -1 if the address contains ASHIFT, so it is not
@@ -11850,7 +11829,7 @@ ix86_decompose_address (rtx addr, struct ix86_addr
base = addr;
else if (GET_CODE (addr) == SUBREG)
{
- if (ix86_address_subreg_operand (SUBREG_REG (addr)))
+ if (REG_P (SUBREG_REG (addr)))
base = addr;
else
return 0;
@@ -11914,7 +11893,7 @@ ix86_decompose_address (rtx addr, struct ix86_addr
break;
case SUBREG:
- if (!ix86_address_subreg_operand (SUBREG_REG (op)))
+ if (!REG_P (SUBREG_REG (op)))
return 0;
/* FALLTHRU */
@@ -11967,18 +11946,12 @@ ix86_decompose_address (rtx addr, struct ix86_addr
if (REG_P (index))
;
else if (GET_CODE (index) == SUBREG
- && ix86_address_subreg_operand (SUBREG_REG (index)))
+ && REG_P (SUBREG_REG (index)))
;
else
return 0;
}
-/* Address override works only on the (%reg) part of %fs:(%reg). */
- if (seg != SEG_DEFAULT
- && ((base && GET_MODE (base) != word_mode)
- || (index && GET_MODE (index) != word_mode)))
- return 0;
-
/* Extract the integral value of scale. */
if (scale_rtx)
{
@@ -12495,6 +12468,45 @@ ix86_legitimize_reload_address (rtx x,
return false;
}
+/* Determine if op is suitable RTX for an address register.
+ Return naked register if a register or a register subreg is
+ found, otherwise return NULL_RTX. */
+
+static rtx
+ix86_validate_address_register (rtx op)
+{
+ enum machine_mode mode = GET_MODE (op);
+
+ /* Only SImode or DImode registers can form the address. */
+ if (mode != SImode && mode != DImode)
+ return NULL_RTX;
+
+ if (REG_P (op))
+ return op;
+ else if (GET_CODE (op) == SUBREG)
+ {
+ rtx reg = SUBREG_REG (op);
+
+ if (!REG_P (reg))
+ return NULL_RTX;
+
+ mode = GET_MODE (reg);
+
+ /* Don't allow SUBREGs that span more than a word. It can
+ lead to spill failures when the register is one word out
+ of a two word structure. */
+ if (GET_MODE_SIZE (mode) > UNITS_PER_WORD)
+ return NULL_RTX;
+
+ /* Allow only SUBREGs of non-eliminable hard registers. */
+ if (register_no_elim_operand (reg, mode))
+ return reg;
+ }
+
+ /* Op is not a register. */
+ return NULL_RTX;
+}
+
/* Recognizes RTL expressions that are valid memory addresses for an
instruction. The MODE argument is the machine mode for the MEM
expression that wants to use this address.
@@ -12510,6 +12522,7 @@ ix86_legitimate_address_p (enum machine_mode mode
struct ix86_address parts;
rtx base, index, disp;
HOST_WIDE_INT scale;
+ enum ix86_address_seg seg;
if (ix86_decompose_address (addr, &parts) <= 0)
/* Decomposition failed. */
@@ -12519,23 +12532,16 @@ ix86_legitimate_address_p (enum machine_mode mode
index = parts.index;
disp = parts.disp;
scale = parts.scale;
+ seg = parts.seg;
/* Validate base register. */
if (base)
{
- rtx reg;
+ rtx reg = ix86_validate_address_register (base);
- if (REG_P (base))
- reg = base;
- else if (GET_CODE (base) == SUBREG && REG_P (SUBREG_REG (base)))
- reg = SUBREG_REG (base);
- else
- /* Base is not a register. */
+ if (reg == NULL_RTX)
return false;
- if (GET_MODE (base) != SImode && GET_MODE (base) != DImode)
- return false;
-
if ((strict && ! REG_OK_FOR_BASE_STRICT_P (reg))
|| (! strict && ! REG_OK_FOR_BASE_NONSTRICT_P (reg)))
/* Base is not valid. */
@@ -12545,19 +12551,11 @@ ix86_legitimate_address_p (enum machine_mode mode
/* Validate index register. */
if (index)
{
- rtx reg;
+ rtx reg = ix86_validate_address_register (index);
- if (REG_P (index))
- reg = index;
- else if (GET_CODE (index) == SUBREG && REG_P (SUBREG_REG (index)))
- reg = SUBREG_REG (index);
- else
- /* Index is not a register. */
+ if (reg == NULL_RTX)
return false;
- if (GET_MODE (index) != SImode && GET_MODE (index) != DImode)
- return false;
-
if ((strict && ! REG_OK_FOR_INDEX_STRICT_P (reg))
|| (! strict && ! REG_OK_FOR_INDEX_NONSTRICT_P (reg)))
/* Index is not valid. */
@@ -12569,6 +12567,12 @@ ix86_legitimate_address_p (enum machine_mode mode
&& GET_MODE (base) != GET_MODE (index))
return false;
+ /* Address override works only on the (%reg) part of %fs:(%reg). */
+ if (seg != SEG_DEFAULT
+ && ((base && GET_MODE (base) != word_mode)
+ || (index && GET_MODE (index) != word_mode)))
+ return false;
+
/* Validate scale factor. */
if (scale != 1)
{
