https://gcc.gnu.org/g:cdcfeb5aa467d17024891bdbc218531151b0f1d6
commit cdcfeb5aa467d17024891bdbc218531151b0f1d6
Author: Michael Meissner <meiss...@linux.ibm.com>
Date: Thu Apr 25 20:24:59 2024 -0400
Add -mmfspr option.
2024-04-25 Michael Meissner <meiss...@linux.ibm.com>
gcc/
* config/rs6000/rs6000-cpus.def (ISA_MASKS_2_7_SERVER): Add -mmfspr.
(POWERPC_MASKS): Likewise.
* config/rs6000/rs6000.cc (rs6000_register_move_cost): Check
-mmfspr.
* config/rs6000/rs6000.opt (-mmfspr): New option.
Diff:
---
gcc/config/rs6000/rs6000-cpus.def | 2 ++
gcc/config/rs6000/rs6000.cc | 3 ++-
gcc/config/rs6000/rs6000.opt | 4 ++++
3 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/gcc/config/rs6000/rs6000-cpus.def
b/gcc/config/rs6000/rs6000-cpus.def
index 7ea3ce09c8d..ecb9471d84a 100644
--- a/gcc/config/rs6000/rs6000-cpus.def
+++ b/gcc/config/rs6000/rs6000-cpus.def
@@ -51,6 +51,7 @@
| OPTION_MASK_CRYPTO \
| OPTION_MASK_DIRECT_MOVE \
| OPTION_MASK_EFFICIENT_UNALIGNED_VSX \
+ | OPTION_MASK_MFSPR \
| OPTION_MASK_QUAD_MEMORY \
| OPTION_MASK_QUAD_MEMORY_ATOMIC \
| OPTION_MASK_TAR)
@@ -138,6 +139,7 @@
| OPTION_MASK_HTM \
| OPTION_MASK_ISEL \
| OPTION_MASK_MFCRF \
+ | OPTION_MASK_MFSPR \
| OPTION_MASK_MMA \
| OPTION_MASK_MODULO \
| OPTION_MASK_MULHW \
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index e5ebbd58cc0..4df4259335b 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -22816,7 +22816,8 @@ rs6000_register_move_cost (machine_mode mode,
/* Make moves from SPR registers (LR, CTR, TAR) more expensive so that the
register allocator does not think of these registers are useful for saving
results. */
- else if (reg_classes_intersect_p (from, SPECIAL_REGS)
+ else if (TARGET_MFSPR
+ && reg_classes_intersect_p (from, SPECIAL_REGS)
&& reg_classes_intersect_p (to, GENERAL_REGS))
{
rclass = from;
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 8e9215a32c2..2cbf7c1db1c 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -607,6 +607,10 @@ mtar
Target Mask(TAR) Var(rs6000_isa_flags)
Generate (do not generate) code using the TAR register.
+mmfspr
+Target Undocumented Mask(MFSPR) Var(rs6000_isa_flags)
+Generate (do not generate) code making move from SPR register expensive.
+
mrelative-jumptables
Target Undocumented Var(rs6000_relative_jumptables) Init(1) Save
