public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
* [PATCH v2] xtensa: Eliminate the use of callee-saved register that saves and restores only once
       [not found] <70bdc2f9-f0ae-cca7-0910-859cacbf5eae.ref@yahoo.co.jp>
@ 2023-01-17  4:12 ` Takayuki 'January June' Suwa
  2023-01-17 11:23   ` Max Filippov
  0 siblings, 1 reply; 4+ messages in thread
From: Takayuki 'January June' Suwa @ 2023-01-17  4:12 UTC (permalink / raw)
  To: GCC Patches; +Cc: Max Filippov

In the case of the CALL0 ABI, values that must be retained before and
after function calls are placed in the callee-saved registers (A12
through A15) and referenced later.  However, it is often the case that
the save and the reference are each only once and a simple register-
register move (the frame pointer is needed to recover the stack pointer
and must be excluded).

e.g. in the following example, if there are no other occurrences of
register A14:

;; before
	; prologue {
  ...
	s32i.n	a14, sp, 16
  ...
	; } prologue
  ...
	mov.n	a14, a6
  ...
	call0	foo
  ...
	mov.n	a8, a14
  ...
	; epilogue {
  ...
	l32i.n	a14, sp, 16
  ...
	; } epilogue

It can be possible like this:

;; after
	; prologue {
  ...
	(deleted)
  ...
	; } prologue
  ...
	s32i.n	a6, sp, 16
  ...
	call0	foo
  ...
	l32i.n	a8, sp, 16
  ...
	; epilogue {
  ...
	(deleted)
  ...
	; } epilogue

This patch introduces a new peephole2 pattern that implements the above.

gcc/ChangeLog:

	* config/xtensa/xtensa.md: New peephole2 pattern that eliminates
	the use of callee-saved register that saves and restores only once
	for other register, by using its stack slot directly.
---
 gcc/config/xtensa/xtensa.md | 60 +++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 98f3c468f8b..fc512346741 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -3024,3 +3024,63 @@ FALLTHRU:;
   operands[1] = GEN_INT (imm0);
   operands[2] = GEN_INT (imm1);
 })
+
+(define_peephole2
+  [(set (match_operand:SI 0 "register_operand")
+	(match_operand:SI 1 "reload_operand"))]
+  "!TARGET_WINDOWED_ABI && df
+   && epilogue_contains (insn)
+   && ! call_used_or_fixed_reg_p (REGNO (operands[0]))
+   && (!frame_pointer_needed
+       || REGNO (operands[0]) != HARD_FRAME_POINTER_REGNUM)"
+  [(const_int 0)]
+{
+  rtx reg = operands[0], pattern;
+  rtx_insn *insnP = NULL, *insnS = NULL, *insnR = NULL;
+  df_ref ref;
+  rtx_insn *insn;
+  for (ref = DF_REG_DEF_CHAIN (REGNO (reg));
+       ref; ref = DF_REF_NEXT_REG (ref))
+    if (DF_REF_CLASS (ref) != DF_REF_REGULAR)
+      continue;
+    else if ((insn = DF_REF_INSN (ref)) == curr_insn)
+      continue;
+    else if (GET_CODE (pattern = PATTERN (insn)) == SET
+	     && rtx_equal_p (SET_DEST (pattern), reg)
+	     && REG_P (SET_SRC (pattern)))
+      {
+	if (insnS)
+	  FAIL;
+	insnS = insn;
+	continue;
+      }
+    else
+      FAIL;
+  for (ref = DF_REG_USE_CHAIN (REGNO (reg));
+       ref; ref = DF_REF_NEXT_REG (ref))
+    if (DF_REF_CLASS (ref) != DF_REF_REGULAR)
+      continue;
+    else if (prologue_contains (insn = DF_REF_INSN (ref)))
+      {
+	insnP = insn;
+	continue;
+      }
+    else if (GET_CODE (pattern = PATTERN (insn)) == SET
+	     && rtx_equal_p (SET_SRC (pattern), reg)
+	     && REG_P (SET_DEST (pattern)))
+      {
+	if (insnR)
+	  FAIL;
+	insnR = insn;
+	continue;
+      }
+    else
+      FAIL;
+  if (!insnP || !insnS || !insnR)
+    FAIL;
+  SET_DEST (PATTERN (insnS)) = copy_rtx (operands[1]);
+  df_insn_rescan (insnS);
+  SET_SRC (PATTERN (insnR)) = copy_rtx (operands[1]);
+  df_insn_rescan (insnR);
+  set_insn_deleted (insnP);
+})
-- 
2.30.2

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] xtensa: Eliminate the use of callee-saved register that saves and restores only once
  2023-01-17  4:12 ` [PATCH v2] xtensa: Eliminate the use of callee-saved register that saves and restores only once Takayuki 'January June' Suwa
@ 2023-01-17 11:23   ` Max Filippov
  2023-01-18  4:23     ` [PATCH v3] " Takayuki 'January June' Suwa
  0 siblings, 1 reply; 4+ messages in thread
From: Max Filippov @ 2023-01-17 11:23 UTC (permalink / raw)
  To: Takayuki 'January June' Suwa; +Cc: GCC Patches

Hi Suwa-san,

On Mon, Jan 16, 2023 at 8:12 PM Takayuki 'January June' Suwa
<jjsuwa_sys3175@yahoo.co.jp> wrote:
>
> In the case of the CALL0 ABI, values that must be retained before and
> after function calls are placed in the callee-saved registers (A12
> through A15) and referenced later.  However, it is often the case that
> the save and the reference are each only once and a simple register-
> register move (the frame pointer is needed to recover the stack pointer
> and must be excluded).
>
> e.g. in the following example, if there are no other occurrences of
> register A14:
>
> ;; before
>         ; prologue {
>   ...
>         s32i.n  a14, sp, 16
>   ...
>         ; } prologue
>   ...
>         mov.n   a14, a6
>   ...
>         call0   foo
>   ...
>         mov.n   a8, a14
>   ...
>         ; epilogue {
>   ...
>         l32i.n  a14, sp, 16
>   ...
>         ; } epilogue
>
> It can be possible like this:
>
> ;; after
>         ; prologue {
>   ...
>         (deleted)
>   ...
>         ; } prologue
>   ...
>         s32i.n  a6, sp, 16
>   ...
>         call0   foo
>   ...
>         l32i.n  a8, sp, 16
>   ...
>         ; epilogue {
>   ...
>         (deleted)
>   ...
>         ; } epilogue
>
> This patch introduces a new peephole2 pattern that implements the above.
>
> gcc/ChangeLog:
>
>         * config/xtensa/xtensa.md: New peephole2 pattern that eliminates
>         the use of callee-saved register that saves and restores only once
>         for other register, by using its stack slot directly.
> ---
>  gcc/config/xtensa/xtensa.md | 60 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)

There's still a few regressions in tests with -fcompare-debug because
code generated with -g and without it is different:

+FAIL: gcc.dg/pr41241.c (test for excess errors)
+FAIL: gcc.dg/pr48159-1.c (test for excess errors)
+FAIL: gcc.dg/pr65521.c (test for excess errors)
+FAIL: gcc.dg/torture/pr42878-1.c   -O2  (test for excess errors)
+FAIL: gcc.dg/torture/pr42878-1.c   -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions  (test for
excess errors)
+FAIL: gcc.dg/torture/pr42878-1.c   -O3 -g  (test for excess errors)
+FAIL: gcc.dg/torture/pr42878-1.c   -Os  (test for excess errors)
+FAIL: gcc.dg/torture/pr42878-1.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)

E.g. check the following test with -g0 and -g:

gcc/cc1 gcc/testsuite/gcc.dg/torture/pr42878-1.c -mlongcalls
-mtext-section-literals -fdiagnostics-plain-output -O3
-fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer
-finline-functions

-- 
Thanks.
-- Max

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v3] xtensa: Eliminate the use of callee-saved register that saves and restores only once
  2023-01-17 11:23   ` Max Filippov
@ 2023-01-18  4:23     ` Takayuki 'January June' Suwa
  2023-01-18  9:04       ` Max Filippov
  0 siblings, 1 reply; 4+ messages in thread
From: Takayuki 'January June' Suwa @ 2023-01-18  4:23 UTC (permalink / raw)
  To: GCC Patches; +Cc: Max Filippov

On 2023/01/17 20:23, Max Filippov wrote:
> Hi Suwa-san,
Hi!

> There's still a few regressions in tests with -fcompare-debug because
> code generated with -g and without it is different:
> E.g. check the following test with -g0 and -g:
Again debug_insn is the problem...

=====
In the case of the CALL0 ABI, values that must be retained before and
after function calls are placed in the callee-saved registers (A12
through A15) and referenced later.  However, it is often the case that
the save and the reference are each only once and a simple register-
register move (the frame pointer is needed to recover the stack pointer
and must be excluded).

e.g. in the following example, if there are no other occurrences of
register A14:

;; before
	; prologue {
  ...
	s32i.n	a14, sp, 16
  ...
	; } prologue
  ...
	mov.n	a14, a6
  ...
	call0	foo
  ...
	mov.n	a8, a14
  ...
	; epilogue {
  ...
	l32i.n	a14, sp, 16
  ...
	; } epilogue

It can be possible like this:

;; after
	; prologue {
  ...
	(deleted)
  ...
	; } prologue
  ...
	s32i.n	a6, sp, 16
  ...
	call0	foo
  ...
	l32i.n	a8, sp, 16
  ...
	; epilogue {
  ...
	(deleted)
  ...
	; } epilogue

This patch introduces a new peephole2 pattern that implements the above.

gcc/ChangeLog:

	* config/xtensa/xtensa.md: New peephole2 pattern that eliminates
	the use of callee-saved register that saves and restores only once
	for other register, by using its stack slot directly.
---
 gcc/config/xtensa/xtensa.md | 62 +++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 98f3c468f8b..2f3b2256d8b 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -3024,3 +3024,65 @@ FALLTHRU:;
   operands[1] = GEN_INT (imm0);
   operands[2] = GEN_INT (imm1);
 })
+
+(define_peephole2
+  [(set (match_operand:SI 0 "register_operand")
+	(match_operand:SI 1 "reload_operand"))]
+  "!TARGET_WINDOWED_ABI && df
+   && epilogue_contains (insn)
+   && ! call_used_or_fixed_reg_p (REGNO (operands[0]))
+   && (!frame_pointer_needed
+       || REGNO (operands[0]) != HARD_FRAME_POINTER_REGNUM)"
+  [(const_int 0)]
+{
+  rtx reg = operands[0], pattern;
+  rtx_insn *insnP = NULL, *insnS = NULL, *insnR = NULL;
+  df_ref ref;
+  rtx_insn *insn;
+  for (ref = DF_REG_DEF_CHAIN (REGNO (reg));
+       ref; ref = DF_REF_NEXT_REG (ref))
+    if (DF_REF_CLASS (ref) != DF_REF_REGULAR
+	|| ! NONJUMP_INSN_P (insn = DF_REF_INSN (ref)))
+      continue;
+    else if (insn == curr_insn)
+      continue;
+    else if (GET_CODE (pattern = PATTERN (insn)) == SET
+	     && rtx_equal_p (SET_DEST (pattern), reg)
+	     && REG_P (SET_SRC (pattern)))
+      {
+	if (insnS)
+	  FAIL;
+	insnS = insn;
+	continue;
+      }
+    else
+      FAIL;
+  for (ref = DF_REG_USE_CHAIN (REGNO (reg));
+       ref; ref = DF_REF_NEXT_REG (ref))
+    if (DF_REF_CLASS (ref) != DF_REF_REGULAR
+	|| ! NONJUMP_INSN_P (insn = DF_REF_INSN (ref)))
+      continue;
+    else if (prologue_contains (insn))
+      {
+	insnP = insn;
+	continue;
+      }
+    else if (GET_CODE (pattern = PATTERN (insn)) == SET
+	     && rtx_equal_p (SET_SRC (pattern), reg)
+	     && REG_P (SET_DEST (pattern)))
+      {
+	if (insnR)
+	  FAIL;
+	insnR = insn;
+	continue;
+      }
+    else
+      FAIL;
+  if (!insnP || !insnS || !insnR)
+    FAIL;
+  SET_DEST (PATTERN (insnS)) = copy_rtx (operands[1]);
+  df_insn_rescan (insnS);
+  SET_SRC (PATTERN (insnR)) = copy_rtx (operands[1]);
+  df_insn_rescan (insnR);
+  set_insn_deleted (insnP);
+})
-- 
2.30.2

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] xtensa: Eliminate the use of callee-saved register that saves and restores only once
  2023-01-18  4:23     ` [PATCH v3] " Takayuki 'January June' Suwa
@ 2023-01-18  9:04       ` Max Filippov
  0 siblings, 0 replies; 4+ messages in thread
From: Max Filippov @ 2023-01-18  9:04 UTC (permalink / raw)
  To: Takayuki 'January June' Suwa; +Cc: GCC Patches

Hi Suwa-san,

On Tue, Jan 17, 2023 at 8:23 PM Takayuki 'January June' Suwa
<jjsuwa_sys3175@yahoo.co.jp> wrote:
> In the case of the CALL0 ABI, values that must be retained before and
> after function calls are placed in the callee-saved registers (A12
> through A15) and referenced later.  However, it is often the case that
> the save and the reference are each only once and a simple register-
> register move (the frame pointer is needed to recover the stack pointer
> and must be excluded).
>
> e.g. in the following example, if there are no other occurrences of
> register A14:
>
> ;; before
>         ; prologue {
>   ...
>         s32i.n  a14, sp, 16
>   ...
>         ; } prologue
>   ...
>         mov.n   a14, a6
>   ...
>         call0   foo
>   ...
>         mov.n   a8, a14
>   ...
>         ; epilogue {
>   ...
>         l32i.n  a14, sp, 16
>   ...
>         ; } epilogue
>
> It can be possible like this:
>
> ;; after
>         ; prologue {
>   ...
>         (deleted)
>   ...
>         ; } prologue
>   ...
>         s32i.n  a6, sp, 16
>   ...
>         call0   foo
>   ...
>         l32i.n  a8, sp, 16
>   ...
>         ; epilogue {
>   ...
>         (deleted)
>   ...
>         ; } epilogue
>
> This patch introduces a new peephole2 pattern that implements the above.
>
> gcc/ChangeLog:
>
>         * config/xtensa/xtensa.md: New peephole2 pattern that eliminates
>         the use of callee-saved register that saves and restores only once
>         for other register, by using its stack slot directly.
> ---
>  gcc/config/xtensa/xtensa.md | 62 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 62 insertions(+)

This change introduces a bunch of different test failures:

FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution,  -O2
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution,  -O3 -g
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution,  -Os
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution,  -O2 -flto
-fno-use-linker-plugin -flto-partition=none
FAIL: gcc.c-torture/execute/builtins/strstr-asm.c execution,  -Os
FAIL: gcc.c-torture/execute/20001130-1.c   -Os  execution test
FAIL: gcc.c-torture/execute/20040311-1.c   -O2  execution test
FAIL: gcc.c-torture/execute/20040311-1.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/20040311-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.c-torture/execute/20121108-1.c   -O2  execution test
FAIL: gcc.c-torture/execute/20121108-1.c   -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions  execution
test
FAIL: gcc.c-torture/execute/20121108-1.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/20121108-1.c   -Os  execution test
FAIL: gcc.c-torture/execute/20121108-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.c-torture/execute/20121108-1.c   -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects  execution test
FAIL: gcc.c-torture/execute/20140622-1.c   -O2  execution test
FAIL: gcc.c-torture/execute/20140622-1.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/20140622-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.c-torture/execute/20141022-1.c   -O2  execution test
FAIL: gcc.c-torture/execute/20141022-1.c   -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions  execution
test
FAIL: gcc.c-torture/execute/20141022-1.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/20141022-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.c-torture/execute/20141022-1.c   -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects  execution test
FAIL: gcc.c-torture/execute/20141107-1.c   -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects  execution test
FAIL: gcc.c-torture/execute/961213-1.c   -Os  execution test
FAIL: gcc.c-torture/execute/builtin-bitops-1.c   -Os  execution test
FAIL: gcc.c-torture/execute/cvt-1.c   -O2  execution test
FAIL: gcc.c-torture/execute/cvt-1.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/cvt-1.c   -Os  execution test
FAIL: gcc.c-torture/execute/cvt-1.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  execution test
FAIL: gcc.c-torture/execute/pr40747.c   -O2  execution test
FAIL: gcc.c-torture/execute/pr40747.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/pr40747.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.c-torture/execute/pr60960.c   -O2  execution test
FAIL: gcc.c-torture/execute/pr60960.c   -O3 -g  execution test
FAIL: gcc.c-torture/execute/pr60960.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.c-torture/execute/pr60960.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  execution test
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution,  -O2
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution,  -O3
-fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer
-finline-functions
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution,  -O3 -g
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution,  -O2 -flto
-fno-use-linker-plugin -flto-partition=none
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution,  -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects
FAIL: gcc.dg/pr103721.c execution test
FAIL: gcc.dg/pr38364.c execution test
FAIL: gcc.dg/pr92301.c execution test
FAIL: gcc.dg/strlenopt-92.c execution test
FAIL: gcc.dg/torture/pr90553.c   -O2  execution test
FAIL: gcc.dg/torture/pr90553.c   -O3 -g  execution test
FAIL: gcc.dg/torture/pr90553.c   -Os  execution test
FAIL: gcc.dg/torture/pr90553.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  execution test
FAIL: gcc.dg/torture/pr90553.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  execution test
FAIL: gcc.dg/torture/stackalign/vararg-1.c   -O2  execution test
FAIL: gcc.dg/torture/stackalign/vararg-1.c   -O2 -fpic execution test
FAIL: gcc.dg/torture/stackalign/vararg-1.c   -O3 -g  execution test
FAIL: gcc.dg/torture/stackalign/vararg-1.c   -O3 -g -fpic execution test
FAIL: gcc.dg/torture/stackalign/vararg-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
FAIL: gcc.dg/torture/stackalign/vararg-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none -fpic execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -O2  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -O3 -g  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -Os  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -O2  -fpic  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -O3 -g  -fpic  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -Os  -fpic  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -O2  -fPIC  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -O3 -g  -fPIC  execution test
FAIL: gcc.dg/torture/tls/thr-init-2.c   -Os  -fPIC  execution test

--
Thanks.
-- Max

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-01-18  9:04 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <70bdc2f9-f0ae-cca7-0910-859cacbf5eae.ref@yahoo.co.jp>
2023-01-17  4:12 ` [PATCH v2] xtensa: Eliminate the use of callee-saved register that saves and restores only once Takayuki 'January June' Suwa
2023-01-17 11:23   ` Max Filippov
2023-01-18  4:23     ` [PATCH v3] " Takayuki 'January June' Suwa
2023-01-18  9:04       ` Max Filippov

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).