public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc(refs/users/segher/heads/cc0)] combine: Delete more CC0 stuff
@ 2020-02-04 21:55 Segher Boessenkool
0 siblings, 0 replies; 4+ messages in thread
From: Segher Boessenkool @ 2020-02-04 21:55 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:ffc694ef3d0e25d906296b28f3d4b5c404821538
commit ffc694ef3d0e25d906296b28f3d4b5c404821538
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date: Sun Sep 22 16:51:59 2019 +0000
combine: Delete more CC0 stuff
Diff:
---
gcc/combine.c | 59 +++++++++++------------------------------------------------
1 file changed, 11 insertions(+), 48 deletions(-)
diff --git a/gcc/combine.c b/gcc/combine.c
index b7b22a0..a43d956 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -33,12 +33,6 @@ along with GCC; see the file COPYING3. If not see
small number of quadruplets of insns A, B, C and D for which
there's high likelihood of success.
- LOG_LINKS does not have links for use of the CC0. They don't
- need to, because the insn that sets the CC0 is always immediately
- before the insn that tests it. So we always regard a branch
- insn as having a logical link to the preceding insn. The same is true
- for an insn explicitly using CC0.
-
We check (with modified_between_p) to avoid combining in such a way
as to move a computation to a place where its value would be different.
@@ -64,16 +58,7 @@ along with GCC; see the file COPYING3. If not see
To simplify substitution, we combine only when the earlier insn(s)
consist of only a single assignment. To simplify updating afterward,
- we never combine when a subroutine call appears in the middle.
-
- Since we do not represent assignments to CC0 explicitly except when that
- is all an insn does, there is no LOG_LINKS entry in an insn that uses
- the condition code for the insn that set the condition code.
- Fortunately, these two insns must be consecutive.
- Therefore, every JUMP_INSN is taken to have an implicit logical link
- to the preceding insn. This is not quite right, since non-jumps can
- also use the condition code; but in practice such insns would not
- combine anyway. */
+ we never combine when a subroutine call appears in the middle. */
#include "config.h"
#include "system.h"
@@ -549,8 +534,8 @@ combine_split_insns (rtx pattern, rtx_insn *insn)
}
/* This is used by find_single_use to locate an rtx in LOC that
- contains exactly one use of DEST, which is typically either a REG
- or CC0. It returns a pointer to the innermost rtx expression
+ contains exactly one use of DEST, which is typically a REG.
+ It returns a pointer to the innermost rtx expression
containing DEST. Appearances of DEST that are being used to
totally replace it are not counted. */
@@ -1111,9 +1096,7 @@ create_log_links (void)
/* Walk the LOG_LINKS of insn B to see if we find a reference to A. Return
true if we found a LOG_LINK that proves that A feeds B. This only works
if there are no instructions between A and B which could have a link
- depending on A, since in that case we would not record a link for B.
- We also check the implicit dependency created by a cc0 setter/user
- pair. */
+ depending on A, since in that case we would not record a link for B. */
static bool
insn_a_feeds_b (rtx_insn *a, rtx_insn *b)
@@ -1769,7 +1752,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
else if (next_active_insn (insn) != i3)
all_adjacent = false;
- /* Can combine only if previous insn is a SET of a REG, a SUBREG or CC0.
+ /* Can combine only if previous insn is a SET of a REG or a SUBREG,
or a PARALLEL consisting of such a SET and CLOBBERs.
If INSN has CLOBBER parallel parts, ignore them for our processing.
@@ -1948,7 +1931,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
|| (DF_INSN_LUID (insn) < last_call_luid && ! CONSTANT_P (src)))
return 0;
- /* DEST must either be a REG or CC0. */
+ /* DEST must be a REG. */
if (REG_P (dest))
{
/* If register alignment is being enforced for multi-word items in all
@@ -3162,7 +3145,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
subst_insn = i3;
- /* Many machines that don't use CC0 have insns that can both perform an
+ /* Many machines have insns that can both perform an
arithmetic operation and set the condition code. These operations will
be represented as a PARALLEL with the first element of the vector
being a COMPARE of an arithmetic operation with the constant zero.
@@ -3899,7 +3882,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
eliminate the copy.
We cannot do this if the destination of the first assignment is a
- condition code register or cc0. We eliminate this case by making sure
+ condition code register. We eliminate this case by making sure
the SET_DEST and SET_SRC have the same mode.
We cannot do this if the destination of the second assignment is
@@ -3993,8 +3976,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
rtx set0 = XVECEXP (newpat, 0, 0);
rtx set1 = XVECEXP (newpat, 0, 1);
- /* Normally, it doesn't matter which of the two is done first,
- but the one that references cc0 can't be the second, and
+ /* Normally, it doesn't matter which of the two is done first, but
one which uses any regs/memory set in between i2 and i3 can't
be first. The PARALLEL might also have been pre-existing in i3,
so we need to make sure that we won't wrongly hoist a SET to i2
@@ -6723,9 +6705,8 @@ simplify_set (rtx x)
SUBST (SET_SRC (x), src);
}
- /* If we are setting CC0 or if the source is a COMPARE, look for the use of
- the comparison result and try to simplify it unless we already have used
- undobuf.other_insn. */
+ /* If the source is a COMPARE, look for the use of the comparison result
+ and try to simplify it unless we already have used undobuf.other_insn. */
if ((GET_MODE_CLASS (mode) == MODE_CC || GET_CODE (src) == COMPARE)
&& (cc_use = find_single_use (dest, subst_insn, &other_insn)) != 0
&& (undobuf.other_insn == 0 || other_insn == undobuf.other_insn)
@@ -14450,7 +14431,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
{
rtx set = single_set (tem_insn);
rtx inner_dest = 0;
- rtx_insn *cc0_setter = NULL;
if (set != 0)
for (inner_dest = SET_DEST (set);
@@ -14491,23 +14471,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
SET_INSN_DELETED (tem_insn);
if (tem_insn == i2)
i2 = NULL;
-
- /* Delete the setter too. */
- if (cc0_setter)
- {
- PATTERN (cc0_setter) = pc_rtx;
- old_notes = REG_NOTES (cc0_setter);
- REG_NOTES (cc0_setter) = NULL;
-
- distribute_notes (old_notes, cc0_setter,
- cc0_setter, NULL,
- NULL_RTX, NULL_RTX, NULL_RTX);
- distribute_links (LOG_LINKS (cc0_setter));
-
- SET_INSN_DELETED (cc0_setter);
- if (cc0_setter == i2)
- i2 = NULL;
- }
}
else
{
^ permalink raw reply [flat|nested] 4+ messages in thread* [gcc(refs/users/segher/heads/cc0)] combine: Delete more CC0 stuff
@ 2020-06-15 19:23 Segher Boessenkool
0 siblings, 0 replies; 4+ messages in thread
From: Segher Boessenkool @ 2020-06-15 19:23 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:66c833e4562e5eaaa2df7e3c89c47095d0375439
commit 66c833e4562e5eaaa2df7e3c89c47095d0375439
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date: Sun Sep 22 16:51:59 2019 +0000
combine: Delete more CC0 stuff
Diff:
---
gcc/combine.c | 59 +++++++++++------------------------------------------------
1 file changed, 11 insertions(+), 48 deletions(-)
diff --git a/gcc/combine.c b/gcc/combine.c
index 55299a3f23d..b02dd9abfc9 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -33,12 +33,6 @@ along with GCC; see the file COPYING3. If not see
small number of quadruplets of insns A, B, C and D for which
there's high likelihood of success.
- LOG_LINKS does not have links for use of the CC0. They don't
- need to, because the insn that sets the CC0 is always immediately
- before the insn that tests it. So we always regard a branch
- insn as having a logical link to the preceding insn. The same is true
- for an insn explicitly using CC0.
-
We check (with modified_between_p) to avoid combining in such a way
as to move a computation to a place where its value would be different.
@@ -64,16 +58,7 @@ along with GCC; see the file COPYING3. If not see
To simplify substitution, we combine only when the earlier insn(s)
consist of only a single assignment. To simplify updating afterward,
- we never combine when a subroutine call appears in the middle.
-
- Since we do not represent assignments to CC0 explicitly except when that
- is all an insn does, there is no LOG_LINKS entry in an insn that uses
- the condition code for the insn that set the condition code.
- Fortunately, these two insns must be consecutive.
- Therefore, every JUMP_INSN is taken to have an implicit logical link
- to the preceding insn. This is not quite right, since non-jumps can
- also use the condition code; but in practice such insns would not
- combine anyway. */
+ we never combine when a subroutine call appears in the middle. */
#include "config.h"
#include "system.h"
@@ -549,8 +534,8 @@ combine_split_insns (rtx pattern, rtx_insn *insn)
}
/* This is used by find_single_use to locate an rtx in LOC that
- contains exactly one use of DEST, which is typically either a REG
- or CC0. It returns a pointer to the innermost rtx expression
+ contains exactly one use of DEST, which is typically a REG.
+ It returns a pointer to the innermost rtx expression
containing DEST. Appearances of DEST that are being used to
totally replace it are not counted. */
@@ -1111,9 +1096,7 @@ create_log_links (void)
/* Walk the LOG_LINKS of insn B to see if we find a reference to A. Return
true if we found a LOG_LINK that proves that A feeds B. This only works
if there are no instructions between A and B which could have a link
- depending on A, since in that case we would not record a link for B.
- We also check the implicit dependency created by a cc0 setter/user
- pair. */
+ depending on A, since in that case we would not record a link for B. */
static bool
insn_a_feeds_b (rtx_insn *a, rtx_insn *b)
@@ -1770,7 +1753,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
else if (next_active_insn (insn) != i3)
all_adjacent = false;
- /* Can combine only if previous insn is a SET of a REG, a SUBREG or CC0.
+ /* Can combine only if previous insn is a SET of a REG or a SUBREG,
or a PARALLEL consisting of such a SET and CLOBBERs.
If INSN has CLOBBER parallel parts, ignore them for our processing.
@@ -1949,7 +1932,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
|| (DF_INSN_LUID (insn) < last_call_luid && ! CONSTANT_P (src)))
return 0;
- /* DEST must either be a REG or CC0. */
+ /* DEST must be a REG. */
if (REG_P (dest))
{
/* If register alignment is being enforced for multi-word items in all
@@ -3163,7 +3146,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
subst_insn = i3;
- /* Many machines that don't use CC0 have insns that can both perform an
+ /* Many machines have insns that can both perform an
arithmetic operation and set the condition code. These operations will
be represented as a PARALLEL with the first element of the vector
being a COMPARE of an arithmetic operation with the constant zero.
@@ -3900,7 +3883,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
eliminate the copy.
We cannot do this if the destination of the first assignment is a
- condition code register or cc0. We eliminate this case by making sure
+ condition code register. We eliminate this case by making sure
the SET_DEST and SET_SRC have the same mode.
We cannot do this if the destination of the second assignment is
@@ -3994,8 +3977,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
rtx set0 = XVECEXP (newpat, 0, 0);
rtx set1 = XVECEXP (newpat, 0, 1);
- /* Normally, it doesn't matter which of the two is done first,
- but the one that references cc0 can't be the second, and
+ /* Normally, it doesn't matter which of the two is done first, but
one which uses any regs/memory set in between i2 and i3 can't
be first. The PARALLEL might also have been pre-existing in i3,
so we need to make sure that we won't wrongly hoist a SET to i2
@@ -6730,9 +6712,8 @@ simplify_set (rtx x)
SUBST (SET_SRC (x), src);
}
- /* If we are setting CC0 or if the source is a COMPARE, look for the use of
- the comparison result and try to simplify it unless we already have used
- undobuf.other_insn. */
+ /* If the source is a COMPARE, look for the use of the comparison result
+ and try to simplify it unless we already have used undobuf.other_insn. */
if ((GET_MODE_CLASS (mode) == MODE_CC || GET_CODE (src) == COMPARE)
&& (cc_use = find_single_use (dest, subst_insn, &other_insn)) != 0
&& (undobuf.other_insn == 0 || other_insn == undobuf.other_insn)
@@ -14457,7 +14438,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
{
rtx set = single_set (tem_insn);
rtx inner_dest = 0;
- rtx_insn *cc0_setter = NULL;
if (set != 0)
for (inner_dest = SET_DEST (set);
@@ -14498,23 +14478,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
SET_INSN_DELETED (tem_insn);
if (tem_insn == i2)
i2 = NULL;
-
- /* Delete the setter too. */
- if (cc0_setter)
- {
- PATTERN (cc0_setter) = pc_rtx;
- old_notes = REG_NOTES (cc0_setter);
- REG_NOTES (cc0_setter) = NULL;
-
- distribute_notes (old_notes, cc0_setter,
- cc0_setter, NULL,
- NULL_RTX, NULL_RTX, NULL_RTX);
- distribute_links (LOG_LINKS (cc0_setter));
-
- SET_INSN_DELETED (cc0_setter);
- if (cc0_setter == i2)
- i2 = NULL;
- }
}
else
{
^ permalink raw reply [flat|nested] 4+ messages in thread* [gcc(refs/users/segher/heads/cc0)] combine: Delete more CC0 stuff
@ 2020-12-15 15:51 Segher Boessenkool
0 siblings, 0 replies; 4+ messages in thread
From: Segher Boessenkool @ 2020-12-15 15:51 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:9f836bbfe2afb4a95c656e4d400715fa8f5698f8
commit 9f836bbfe2afb4a95c656e4d400715fa8f5698f8
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date: Sun Sep 22 16:51:59 2019 +0000
combine: Delete more CC0 stuff
Diff:
---
gcc/combine.c | 59 +++++++++++------------------------------------------------
1 file changed, 11 insertions(+), 48 deletions(-)
diff --git a/gcc/combine.c b/gcc/combine.c
index f8670a180eb..4325a801ceb 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -33,12 +33,6 @@ along with GCC; see the file COPYING3. If not see
small number of quadruplets of insns A, B, C and D for which
there's high likelihood of success.
- LOG_LINKS does not have links for use of the CC0. They don't
- need to, because the insn that sets the CC0 is always immediately
- before the insn that tests it. So we always regard a branch
- insn as having a logical link to the preceding insn. The same is true
- for an insn explicitly using CC0.
-
We check (with modified_between_p) to avoid combining in such a way
as to move a computation to a place where its value would be different.
@@ -64,16 +58,7 @@ along with GCC; see the file COPYING3. If not see
To simplify substitution, we combine only when the earlier insn(s)
consist of only a single assignment. To simplify updating afterward,
- we never combine when a subroutine call appears in the middle.
-
- Since we do not represent assignments to CC0 explicitly except when that
- is all an insn does, there is no LOG_LINKS entry in an insn that uses
- the condition code for the insn that set the condition code.
- Fortunately, these two insns must be consecutive.
- Therefore, every JUMP_INSN is taken to have an implicit logical link
- to the preceding insn. This is not quite right, since non-jumps can
- also use the condition code; but in practice such insns would not
- combine anyway. */
+ we never combine when a subroutine call appears in the middle. */
#include "config.h"
#include "system.h"
@@ -549,8 +534,8 @@ combine_split_insns (rtx pattern, rtx_insn *insn)
}
/* This is used by find_single_use to locate an rtx in LOC that
- contains exactly one use of DEST, which is typically either a REG
- or CC0. It returns a pointer to the innermost rtx expression
+ contains exactly one use of DEST, which is typically a REG.
+ It returns a pointer to the innermost rtx expression
containing DEST. Appearances of DEST that are being used to
totally replace it are not counted. */
@@ -1111,9 +1096,7 @@ create_log_links (void)
/* Walk the LOG_LINKS of insn B to see if we find a reference to A. Return
true if we found a LOG_LINK that proves that A feeds B. This only works
if there are no instructions between A and B which could have a link
- depending on A, since in that case we would not record a link for B.
- We also check the implicit dependency created by a cc0 setter/user
- pair. */
+ depending on A, since in that case we would not record a link for B. */
static bool
insn_a_feeds_b (rtx_insn *a, rtx_insn *b)
@@ -1770,7 +1753,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
else if (next_active_insn (insn) != i3)
all_adjacent = false;
- /* Can combine only if previous insn is a SET of a REG, a SUBREG or CC0.
+ /* Can combine only if previous insn is a SET of a REG or a SUBREG,
or a PARALLEL consisting of such a SET and CLOBBERs.
If INSN has CLOBBER parallel parts, ignore them for our processing.
@@ -1949,7 +1932,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
|| (DF_INSN_LUID (insn) < last_call_luid && ! CONSTANT_P (src)))
return 0;
- /* DEST must either be a REG or CC0. */
+ /* DEST must be a REG. */
if (REG_P (dest))
{
/* If register alignment is being enforced for multi-word items in all
@@ -3164,7 +3147,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
subst_insn = i3;
- /* Many machines that don't use CC0 have insns that can both perform an
+ /* Many machines have insns that can both perform an
arithmetic operation and set the condition code. These operations will
be represented as a PARALLEL with the first element of the vector
being a COMPARE of an arithmetic operation with the constant zero.
@@ -3901,7 +3884,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
eliminate the copy.
We cannot do this if the destination of the first assignment is a
- condition code register or cc0. We eliminate this case by making sure
+ condition code register. We eliminate this case by making sure
the SET_DEST and SET_SRC have the same mode.
We cannot do this if the destination of the second assignment is
@@ -3995,8 +3978,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
rtx set0 = XVECEXP (newpat, 0, 0);
rtx set1 = XVECEXP (newpat, 0, 1);
- /* Normally, it doesn't matter which of the two is done first,
- but the one that references cc0 can't be the second, and
+ /* Normally, it doesn't matter which of the two is done first, but
one which uses any regs/memory set in between i2 and i3 can't
be first. The PARALLEL might also have been pre-existing in i3,
so we need to make sure that we won't wrongly hoist a SET to i2
@@ -6731,9 +6713,8 @@ simplify_set (rtx x)
SUBST (SET_SRC (x), src);
}
- /* If we are setting CC0 or if the source is a COMPARE, look for the use of
- the comparison result and try to simplify it unless we already have used
- undobuf.other_insn. */
+ /* If the source is a COMPARE, look for the use of the comparison result
+ and try to simplify it unless we already have used undobuf.other_insn. */
if ((GET_MODE_CLASS (mode) == MODE_CC || GET_CODE (src) == COMPARE)
&& (cc_use = find_single_use (dest, subst_insn, &other_insn)) != 0
&& (undobuf.other_insn == 0 || other_insn == undobuf.other_insn)
@@ -14479,7 +14460,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
{
rtx set = single_set (tem_insn);
rtx inner_dest = 0;
- rtx_insn *cc0_setter = NULL;
if (set != 0)
for (inner_dest = SET_DEST (set);
@@ -14520,23 +14500,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
SET_INSN_DELETED (tem_insn);
if (tem_insn == i2)
i2 = NULL;
-
- /* Delete the setter too. */
- if (cc0_setter)
- {
- PATTERN (cc0_setter) = pc_rtx;
- old_notes = REG_NOTES (cc0_setter);
- REG_NOTES (cc0_setter) = NULL;
-
- distribute_notes (old_notes, cc0_setter,
- cc0_setter, NULL,
- NULL_RTX, NULL_RTX, NULL_RTX);
- distribute_links (LOG_LINKS (cc0_setter));
-
- SET_INSN_DELETED (cc0_setter);
- if (cc0_setter == i2)
- i2 = NULL;
- }
}
else
{
^ permalink raw reply [flat|nested] 4+ messages in thread* [gcc(refs/users/segher/heads/cc0)] combine: Delete more CC0 stuff
@ 2020-12-15 17:04 Segher Boessenkool
0 siblings, 0 replies; 4+ messages in thread
From: Segher Boessenkool @ 2020-12-15 17:04 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:cb3a43403837c617f3df90f5b323bcd78d4ffbee
commit cb3a43403837c617f3df90f5b323bcd78d4ffbee
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date: Sun Sep 22 16:51:59 2019 +0000
combine: Delete more CC0 stuff
Diff:
---
gcc/combine.c | 59 +++++++++++------------------------------------------------
1 file changed, 11 insertions(+), 48 deletions(-)
diff --git a/gcc/combine.c b/gcc/combine.c
index f8670a180eb..4325a801ceb 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -33,12 +33,6 @@ along with GCC; see the file COPYING3. If not see
small number of quadruplets of insns A, B, C and D for which
there's high likelihood of success.
- LOG_LINKS does not have links for use of the CC0. They don't
- need to, because the insn that sets the CC0 is always immediately
- before the insn that tests it. So we always regard a branch
- insn as having a logical link to the preceding insn. The same is true
- for an insn explicitly using CC0.
-
We check (with modified_between_p) to avoid combining in such a way
as to move a computation to a place where its value would be different.
@@ -64,16 +58,7 @@ along with GCC; see the file COPYING3. If not see
To simplify substitution, we combine only when the earlier insn(s)
consist of only a single assignment. To simplify updating afterward,
- we never combine when a subroutine call appears in the middle.
-
- Since we do not represent assignments to CC0 explicitly except when that
- is all an insn does, there is no LOG_LINKS entry in an insn that uses
- the condition code for the insn that set the condition code.
- Fortunately, these two insns must be consecutive.
- Therefore, every JUMP_INSN is taken to have an implicit logical link
- to the preceding insn. This is not quite right, since non-jumps can
- also use the condition code; but in practice such insns would not
- combine anyway. */
+ we never combine when a subroutine call appears in the middle. */
#include "config.h"
#include "system.h"
@@ -549,8 +534,8 @@ combine_split_insns (rtx pattern, rtx_insn *insn)
}
/* This is used by find_single_use to locate an rtx in LOC that
- contains exactly one use of DEST, which is typically either a REG
- or CC0. It returns a pointer to the innermost rtx expression
+ contains exactly one use of DEST, which is typically a REG.
+ It returns a pointer to the innermost rtx expression
containing DEST. Appearances of DEST that are being used to
totally replace it are not counted. */
@@ -1111,9 +1096,7 @@ create_log_links (void)
/* Walk the LOG_LINKS of insn B to see if we find a reference to A. Return
true if we found a LOG_LINK that proves that A feeds B. This only works
if there are no instructions between A and B which could have a link
- depending on A, since in that case we would not record a link for B.
- We also check the implicit dependency created by a cc0 setter/user
- pair. */
+ depending on A, since in that case we would not record a link for B. */
static bool
insn_a_feeds_b (rtx_insn *a, rtx_insn *b)
@@ -1770,7 +1753,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
else if (next_active_insn (insn) != i3)
all_adjacent = false;
- /* Can combine only if previous insn is a SET of a REG, a SUBREG or CC0.
+ /* Can combine only if previous insn is a SET of a REG or a SUBREG,
or a PARALLEL consisting of such a SET and CLOBBERs.
If INSN has CLOBBER parallel parts, ignore them for our processing.
@@ -1949,7 +1932,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
|| (DF_INSN_LUID (insn) < last_call_luid && ! CONSTANT_P (src)))
return 0;
- /* DEST must either be a REG or CC0. */
+ /* DEST must be a REG. */
if (REG_P (dest))
{
/* If register alignment is being enforced for multi-word items in all
@@ -3164,7 +3147,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
subst_insn = i3;
- /* Many machines that don't use CC0 have insns that can both perform an
+ /* Many machines have insns that can both perform an
arithmetic operation and set the condition code. These operations will
be represented as a PARALLEL with the first element of the vector
being a COMPARE of an arithmetic operation with the constant zero.
@@ -3901,7 +3884,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
eliminate the copy.
We cannot do this if the destination of the first assignment is a
- condition code register or cc0. We eliminate this case by making sure
+ condition code register. We eliminate this case by making sure
the SET_DEST and SET_SRC have the same mode.
We cannot do this if the destination of the second assignment is
@@ -3995,8 +3978,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
rtx set0 = XVECEXP (newpat, 0, 0);
rtx set1 = XVECEXP (newpat, 0, 1);
- /* Normally, it doesn't matter which of the two is done first,
- but the one that references cc0 can't be the second, and
+ /* Normally, it doesn't matter which of the two is done first, but
one which uses any regs/memory set in between i2 and i3 can't
be first. The PARALLEL might also have been pre-existing in i3,
so we need to make sure that we won't wrongly hoist a SET to i2
@@ -6731,9 +6713,8 @@ simplify_set (rtx x)
SUBST (SET_SRC (x), src);
}
- /* If we are setting CC0 or if the source is a COMPARE, look for the use of
- the comparison result and try to simplify it unless we already have used
- undobuf.other_insn. */
+ /* If the source is a COMPARE, look for the use of the comparison result
+ and try to simplify it unless we already have used undobuf.other_insn. */
if ((GET_MODE_CLASS (mode) == MODE_CC || GET_CODE (src) == COMPARE)
&& (cc_use = find_single_use (dest, subst_insn, &other_insn)) != 0
&& (undobuf.other_insn == 0 || other_insn == undobuf.other_insn)
@@ -14479,7 +14460,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
{
rtx set = single_set (tem_insn);
rtx inner_dest = 0;
- rtx_insn *cc0_setter = NULL;
if (set != 0)
for (inner_dest = SET_DEST (set);
@@ -14520,23 +14500,6 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2,
SET_INSN_DELETED (tem_insn);
if (tem_insn == i2)
i2 = NULL;
-
- /* Delete the setter too. */
- if (cc0_setter)
- {
- PATTERN (cc0_setter) = pc_rtx;
- old_notes = REG_NOTES (cc0_setter);
- REG_NOTES (cc0_setter) = NULL;
-
- distribute_notes (old_notes, cc0_setter,
- cc0_setter, NULL,
- NULL_RTX, NULL_RTX, NULL_RTX);
- distribute_links (LOG_LINKS (cc0_setter));
-
- SET_INSN_DELETED (cc0_setter);
- if (cc0_setter == i2)
- i2 = NULL;
- }
}
else
{
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-12-15 17:04 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-04 21:55 [gcc(refs/users/segher/heads/cc0)] combine: Delete more CC0 stuff Segher Boessenkool
2020-06-15 19:23 Segher Boessenkool
2020-12-15 15:51 Segher Boessenkool
2020-12-15 17:04 Segher Boessenkool
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).