...it's really a general RTL predicate, rather than something that depends
on the DF state. Thanks to Segher for the suggestion.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Richard
2017-08-24 Richard Sandiford <richard.sandif...@linaro.org>
gcc/
* df.h (df_read_modify_subreg_p): Remove in favor of...
* rtl.h (read_modify_subreg_p): ...this new function. Take a
const_rtx instead of an rtx.
* cprop.c (local_cprop_find_used_regs): Update accordingly.
* df-problems.c (df_word_lr_mark_ref): Likewise.
* ira-lives.c (mark_pseudo_reg_live): Likewise.
(mark_pseudo_reg_dead): Likewise.
(mark_ref_dead): Likewise.
* reginfo.c (init_subregs_of_mode): Likewise.
* sched-deps.c (sched_analyze_1): Likewise.
* df-scan.c (df_def_record_1): Likewise.
(df_uses_record): Likewise.
(df_read_modify_subreg_p): Remove in favor of...
* rtlanal.c (read_modify_subreg_p): ...this new function. Take a
const_rtx instead of an rtx.
Index: gcc/df.h
===================================================================
--- gcc/df.h 2017-08-24 19:20:31.055856350 +0100
+++ gcc/df.h 2017-08-24 19:20:31.265856538 +0100
@@ -1080,7 +1080,6 @@ extern unsigned int df_hard_reg_used_cou
extern bool df_regs_ever_live_p (unsigned int);
extern void df_set_regs_ever_live (unsigned int, bool);
extern void df_compute_regs_ever_live (bool);
-extern bool df_read_modify_subreg_p (rtx);
extern void df_scan_verify (void);
Index: gcc/rtl.h
===================================================================
--- gcc/rtl.h 2017-08-24 19:20:31.055856350 +0100
+++ gcc/rtl.h 2017-08-24 19:20:31.266856539 +0100
@@ -2176,6 +2176,7 @@ extern unsigned int subreg_lsb_1 (machin
unsigned int);
extern unsigned int subreg_size_offset_from_lsb (unsigned int, unsigned int,
unsigned int);
+extern bool read_modify_subreg_p (const_rtx);
/* Return the subreg byte offset for a subreg whose outer mode is
OUTER_MODE, whose inner mode is INNER_MODE, and where there are
@@ -2800,7 +2801,7 @@ partial_subreg_p (machine_mode outermode
}
/* Likewise return true if X is a subreg that is smaller than the inner
- register. Use df_read_modify_subreg_p to test whether writing to such
+ register. Use read_modify_subreg_p to test whether writing to such
a subreg preserves any part of the inner register. */
inline bool
Index: gcc/cprop.c
===================================================================
--- gcc/cprop.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/cprop.c 2017-08-24 19:20:31.264856537 +0100
@@ -1161,7 +1161,7 @@ local_cprop_find_used_regs (rtx *xptr, v
return;
case SUBREG:
- if (df_read_modify_subreg_p (x))
+ if (read_modify_subreg_p (x))
return;
break;
Index: gcc/df-problems.c
===================================================================
--- gcc/df-problems.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/df-problems.c 2017-08-24 19:20:31.264856537 +0100
@@ -2819,7 +2819,7 @@ df_word_lr_mark_ref (df_ref ref, bool is
return true;
if (GET_CODE (orig_reg) == SUBREG
- && df_read_modify_subreg_p (orig_reg))
+ && read_modify_subreg_p (orig_reg))
{
gcc_assert (DF_REF_FLAGS_IS_SET (ref, DF_REF_PARTIAL));
if (subreg_lowpart_p (orig_reg))
Index: gcc/ira-lives.c
===================================================================
--- gcc/ira-lives.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/ira-lives.c 2017-08-24 19:20:31.265856538 +0100
@@ -364,7 +364,7 @@ mark_hard_reg_live (rtx reg)
static void
mark_pseudo_reg_live (rtx orig_reg, unsigned regno)
{
- if (df_read_modify_subreg_p (orig_reg))
+ if (read_modify_subreg_p (orig_reg))
{
mark_pseudo_regno_subword_live (regno,
subreg_lowpart_p (orig_reg) ? 0 : 1);
@@ -489,7 +489,7 @@ mark_hard_reg_dead (rtx reg)
static void
mark_pseudo_reg_dead (rtx orig_reg, unsigned regno)
{
- if (df_read_modify_subreg_p (orig_reg))
+ if (read_modify_subreg_p (orig_reg))
{
mark_pseudo_regno_subword_dead (regno,
subreg_lowpart_p (orig_reg) ? 0 : 1);
@@ -515,7 +515,7 @@ mark_ref_dead (df_ref def)
if (DF_REF_FLAGS_IS_SET (def, DF_REF_PARTIAL)
&& (GET_CODE (orig_reg) != SUBREG
|| REGNO (reg) < FIRST_PSEUDO_REGISTER
- || !df_read_modify_subreg_p (orig_reg)))
+ || !read_modify_subreg_p (orig_reg)))
return;
if (REGNO (reg) >= FIRST_PSEUDO_REGISTER)
Index: gcc/reginfo.c
===================================================================
--- gcc/reginfo.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/reginfo.c 2017-08-24 19:20:31.265856538 +0100
@@ -1356,7 +1356,7 @@ init_subregs_of_mode (void)
df_ref def;
FOR_EACH_INSN_DEF (def, insn)
if (DF_REF_FLAGS_IS_SET (def, DF_REF_PARTIAL)
- && df_read_modify_subreg_p (DF_REF_REG (def)))
+ && read_modify_subreg_p (DF_REF_REG (def)))
record_subregs_of_mode (DF_REF_REG (def), true);
}
}
Index: gcc/sched-deps.c
===================================================================
--- gcc/sched-deps.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/sched-deps.c 2017-08-24 19:20:31.267856540 +0100
@@ -2419,7 +2419,7 @@ sched_analyze_1 (struct deps_desc *deps,
{
if (GET_CODE (dest) == STRICT_LOW_PART
|| GET_CODE (dest) == ZERO_EXTRACT
- || df_read_modify_subreg_p (dest))
+ || read_modify_subreg_p (dest))
{
/* These both read and modify the result. We must handle
them as writes to get proper dependencies for following
Index: gcc/df-scan.c
===================================================================
--- gcc/df-scan.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/df-scan.c 2017-08-24 19:20:31.265856538 +0100
@@ -2623,23 +2623,6 @@ df_ref_record (enum df_ref_class cl,
}
-/* A set to a non-paradoxical SUBREG for which the number of word_mode units
- covered by the outer mode is smaller than that covered by the inner mode,
- is a read-modify-write operation.
- This function returns true iff the SUBREG X is such a SUBREG. */
-
-bool
-df_read_modify_subreg_p (rtx x)
-{
- unsigned int isize;
-
- if (!partial_subreg_p (x))
- return false;
- isize = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
- return isize > REGMODE_NATURAL_SIZE (GET_MODE (SUBREG_REG (x)));
-}
-
-
/* Process all the registers defined in the rtx pointed by LOC.
Autoincrement/decrement definitions will be picked up by df_uses_record.
Any change here has to be matched in df_find_hard_reg_defs_1. */
@@ -2695,7 +2678,7 @@ df_def_record_1 (struct df_collection_re
}
else if (GET_CODE (dst) == SUBREG && REG_P (SUBREG_REG (dst)))
{
- if (df_read_modify_subreg_p (dst))
+ if (read_modify_subreg_p (dst))
flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL;
flags |= DF_REF_SUBREG;
@@ -2909,7 +2892,7 @@ df_uses_record (struct df_collection_rec
switch (GET_CODE (dst))
{
case SUBREG:
- if (df_read_modify_subreg_p (dst))
+ if (read_modify_subreg_p (dst))
{
df_uses_record (collection_rec, &SUBREG_REG (dst),
DF_REF_REG_USE, bb, insn_info,
Index: gcc/rtlanal.c
===================================================================
--- gcc/rtlanal.c 2017-08-24 19:20:31.055856350 +0100
+++ gcc/rtlanal.c 2017-08-24 19:20:31.266856539 +0100
@@ -1357,6 +1357,22 @@ modified_in_p (const_rtx x, const_rtx in
return 0;
}
+
+/* Return true if X is a SUBREG and if storing a value to X would
+ preserve some of its SUBREG_REG. For example, on a normal 32-bit
+ target, using a SUBREG to store to one half of a DImode REG would
+ preserve the other half. */
+
+bool
+read_modify_subreg_p (const_rtx x)
+{
+ unsigned int isize;
+
+ if (!partial_subreg_p (x))
+ return false;
+ isize = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
+ return isize > REGMODE_NATURAL_SIZE (GET_MODE (SUBREG_REG (x)));
+}
/* Helper function for set_of. */
struct set_of_data
