Hi,
I would like to have a ping for these patches.
BR,
Jeff(Jiufu Guo)
Jiufu Guo <guoji...@linux.ibm.com> writes:
> Hi,
>
> Sometimes, a complicated constant is built via 3(or more)
> instructions. Generally speaking, it would not be as fast
> as loading it from the constant pool (as the discussions in
> PR63281):
> "ld" is one instruction. If consider "address/toc" adjust,
> we may count it as 2 instructions. And "pld" may need fewer
> cycles.
>
> Adding --param=rs6000-min-insns-constant-in-pool helps to
> control the instruction number threshold for different scenarios.
>
> As known, because the constant is load from memory by this
> patch, so this functionality may affect the cache missing.
> While, IMHO, this patch would be still do the right thing.
>
> Compare with the previous version:
> This patch serie adds one more patch to tune the threshold
> for power10.
>
> Boostrap & regtest pass on ppc64{,le}.
> Is this ok for trunk?
>
> BR,
> Jeff (Jiufu Guo)
>
> PR target/63281
>
> gcc/ChangeLog:
>
> * config/rs6000/rs6000.cc (rs6000_emit_set_const): Split constant to
> memory for -m64.
> * config/rs6000/rs6000.opt (rs6000-min-insns-constant-in-pool): New
> parameter.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/powerpc/const_anchors.c: Test final-rtl.
> * gcc.target/powerpc/parall_5insn_const.c: Add option
> --param=rs6000-min-insns-constant-in-pool=5 to keep the original test.
> * gcc.target/powerpc/pr106550.c: Likewise.
> * gcc.target/powerpc/pr106550_1.c: Likewise.
> * gcc.target/powerpc/pr93012.c: Likewise.
> * gcc.target/powerpc/pr87870.c: Update instruction counts.
> * gcc.target/powerpc/pr63281.c: New test.
>
>
> ---
> gcc/config/rs6000/rs6000.cc | 19 +++++++++++++++++++
> gcc/config/rs6000/rs6000.opt | 5 +++++
> .../gcc.target/powerpc/const_anchors.c | 5 +++--
> .../gcc.target/powerpc/parall_5insn_const.c | 2 +-
> gcc/testsuite/gcc.target/powerpc/pr106550.c | 2 +-
> gcc/testsuite/gcc.target/powerpc/pr106550_1.c | 2 +-
> gcc/testsuite/gcc.target/powerpc/pr63281.c | 11 +++++++++++
> gcc/testsuite/gcc.target/powerpc/pr87870.c | 5 ++++-
> gcc/testsuite/gcc.target/powerpc/pr93012.c | 2 +-
> 9 files changed, 46 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr63281.c
>
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index 2046a831938..ec384e87868 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -10240,6 +10240,25 @@ rs6000_emit_set_const (rtx dest, rtx source)
> c = sext_hwi (c, 32);
> emit_move_insn (lo, GEN_INT (c));
> }
> +
> + /* Use base_reg_operand to avoid spliting "r0=xxx" to "r0=[r0+off]"
> + after RA when reusing the DEST register to build the value. */
> + else if ((can_create_pseudo_p () || base_reg_operand (dest, mode))
> + && num_insns_constant (source, mode)
> + > rs6000_min_insns_constant_in_pool
> + && TARGET_64BIT)
> + {
> + rtx sym = force_const_mem (mode, source);
> + if (TARGET_TOC && SYMBOL_REF_P (XEXP (sym, 0))
> + && use_toc_relative_ref (XEXP (sym, 0), mode))
> + {
> + rtx toc = create_TOC_reference (XEXP (sym, 0), dest);
> + sym = gen_const_mem (mode, toc);
> + set_mem_alias_set (sym, get_TOC_alias_set ());
> + }
> +
> + emit_move_insn (dest, sym);
> + }
> else
> rs6000_emit_set_long_const (dest, c);
> break;
> diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
> index e8ca70340df..a1c0d1e89c5 100644
> --- a/gcc/config/rs6000/rs6000.opt
> +++ b/gcc/config/rs6000/rs6000.opt
> @@ -679,3 +679,8 @@ default value is 4.
> Target Undocumented Joined UInteger Var(rs6000_vect_unroll_reduc_threshold)
> Init(1) Param
> When reduction factor computed for a loop exceeds the threshold specified by
> this parameter, prefer to unroll this loop. The default value is 1.
> +
> +-param=rs6000-min-insns-constant-in-pool=
> +Target Undocumented Joined UInteger Var(rs6000_min_insns_constant_in_pool)
> Init(2) IntegerRange(2, 5) Param
> +The minimum instruction number of building a constant to force loading it
> from
> +the constant pool.
> \ No newline at end of file
> diff --git a/gcc/testsuite/gcc.target/powerpc/const_anchors.c
> b/gcc/testsuite/gcc.target/powerpc/const_anchors.c
> index 542e2674b12..682e773d506 100644
> --- a/gcc/testsuite/gcc.target/powerpc/const_anchors.c
> +++ b/gcc/testsuite/gcc.target/powerpc/const_anchors.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile { target has_arch_ppc64 } } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -fdump-rtl-final" } */
>
> #define C1 0x2351847027482577ULL
> #define C2 0x2351847027482578ULL
> @@ -17,4 +17,5 @@ void __attribute__ ((noinline)) foo1 (long long *a, long
> long b)
> *a++ = C2;
> }
>
> -/* { dg-final { scan-assembler-times {\maddi\M} 2 } } */
> +/* { dg-final { scan-rtl-dump-times {\madddi3\M} 2 "final" } } */
> +
> diff --git a/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c
> b/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c
> index e3a9a7264cf..e39479bbf86 100644
> --- a/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c
> +++ b/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2 -mno-prefixed -save-temps" } */
> +/* { dg-options "-O2 -mno-prefixed
> --param=rs6000-min-insns-constant-in-pool=5 -save-temps" } */
> /* { dg-require-effective-target has_arch_ppc64 } */
>
> /* { dg-final { scan-assembler-times {\mlis\M} 4 } } */
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr106550.c
> b/gcc/testsuite/gcc.target/powerpc/pr106550.c
> index 92b76ac8811..2b12a7445b3 100644
> --- a/gcc/testsuite/gcc.target/powerpc/pr106550.c
> +++ b/gcc/testsuite/gcc.target/powerpc/pr106550.c
> @@ -1,5 +1,5 @@
> /* PR target/106550 */
> -/* { dg-options "-O2 -mdejagnu-cpu=power10" } */
> +/* { dg-options "-O2 -mdejagnu-cpu=power10
> --param=rs6000-min-insns-constant-in-pool=3" } */
> /* { dg-require-effective-target has_arch_ppc64 } */
>
> void
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr106550_1.c
> b/gcc/testsuite/gcc.target/powerpc/pr106550_1.c
> index 5ab40d71a56..9da644578a5 100644
> --- a/gcc/testsuite/gcc.target/powerpc/pr106550_1.c
> +++ b/gcc/testsuite/gcc.target/powerpc/pr106550_1.c
> @@ -1,7 +1,7 @@
> /* PR target/106550 */
> /* { dg-require-effective-target power10_ok } */
> /* { dg-require-effective-target has_arch_ppc64 } */
> -/* { dg-options "-O2 -mdejagnu-cpu=power10 -fdisable-rtl-split1" } */
> +/* { dg-options "-O2 -mdejagnu-cpu=power10 -fdisable-rtl-split1
> --param=rs6000-min-insns-constant-in-pool=5" } */
> /* force the constant splitter run after RA: -fdisable-rtl-split1. */
>
> void
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr63281.c
> b/gcc/testsuite/gcc.target/powerpc/pr63281.c
> new file mode 100644
> index 00000000000..9763a7181fc
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr63281.c
> @@ -0,0 +1,11 @@
> +/* Check loading constant from memory pool. */
> +/* { dg-options "-O2 -mpowerpc64" } */
> +
> +void
> +foo (unsigned long long *a)
> +{
> + *a++ = 0x2351847027482577ULL;
> +}
> +
> +/* { dg-final { scan-assembler-times {\mp?ld\M} 1 { target { lp64 } } } } */
> +
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr87870.c
> b/gcc/testsuite/gcc.target/powerpc/pr87870.c
> index d2108ac3386..09b2e8de901 100644
> --- a/gcc/testsuite/gcc.target/powerpc/pr87870.c
> +++ b/gcc/testsuite/gcc.target/powerpc/pr87870.c
> @@ -25,4 +25,7 @@ test3 (void)
> return ((__int128)0xdeadbeefcafebabe << 64) | 0xfacefeedbaaaaaad;
> }
>
> -/* { dg-final { scan-assembler-not {\mld\M} } } */
> +/* test3 is using "ld" to load the value to r3 and r4. So there are 2 'ld's
> + test0, test1 and test2 are using "li", then check 6 'li's. */
> +/* { dg-final { scan-assembler-times {\mp?ld\M} 2 } } */
> +/* { dg-final { scan-assembler-times {\mli\M} 6 } } */
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr93012.c
> b/gcc/testsuite/gcc.target/powerpc/pr93012.c
> index 4f764d0576f..a89a24aee36 100644
> --- a/gcc/testsuite/gcc.target/powerpc/pr93012.c
> +++ b/gcc/testsuite/gcc.target/powerpc/pr93012.c
> @@ -1,6 +1,6 @@
> /* PR target/93012 */
> /* { dg-do compile { target lp64 } } */
> -/* { dg-options "-O2 -std=c99" } */
> +/* { dg-options "-O2 -std=c99 --param=rs6000-min-insns-constant-in-pool=5" }
> */
>
> unsigned long long msk66() { return 0x6666666666666666ULL; }
> unsigned long long mskih() { return 0xabcd1234abcd1234ULL; }
