TARGET_MODE_REP_EXTENDED is supposed to match LOAD_EXTEND_OP, so this
adds an implementation using the same logic as in LOAD_EXTEND_OP.
This reduces the number of extension operations, as evidenced in the
reduction of dynamic instructions for the xz benchmark in SPEC CPU:
# dynamic instructions
baseline new improvement
xz, workload 1 384681308026 374464538911 2.66%
xz, workload 2 985995327109 974304030498 1.19%
xz, workload 3 545372994523 533717744260 2.14%
The shift-shift-2.c testcase needs to be adjusted, as it will no
longer use slliw/slriw for sub5, but will instead emit slli/slri.
No new regressions runnung the riscv.exp suite.
gcc/ChangeLog:
* config/riscv/riscv.cc (riscv_mode_rep_extended):
(TARGET_MODE_REP_EXTENDED): Implement.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/shift-shift-2.c: Adjust.
Signed-off-by: Philipp Tomsich <philipp.toms...@vrull.eu>
---
gcc/config/riscv/riscv.cc | 15 +++++++++++++++
gcc/testsuite/gcc.target/riscv/shift-shift-2.c | 2 --
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 675d92c0961..cf829f390ab 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -5053,6 +5053,18 @@ riscv_hard_regno_mode_ok (unsigned int regno,
machine_mode mode)
return true;
}
+/* Implement TARGET_MODE_REP_EXTENDED. */
+
+static int
+riscv_mode_rep_extended (scalar_int_mode mode, scalar_int_mode mode_rep)
+{
+ /* On 64-bit targets, SImode register values are sign-extended to DImode. */
+ if (TARGET_64BIT && mode == SImode && mode_rep == DImode)
+ return SIGN_EXTEND;
+
+ return UNKNOWN;
+}
+
/* Implement TARGET_MODES_TIEABLE_P.
Don't allow floating-point modes to be tied, since type punning of
@@ -6153,6 +6165,9 @@ riscv_init_libfuncs (void)
#undef TARGET_HARD_REGNO_MODE_OK
#define TARGET_HARD_REGNO_MODE_OK riscv_hard_regno_mode_ok
+#undef TARGET_MODE_REP_EXTENDED
+#define TARGET_MODE_REP_EXTENDED riscv_mode_rep_extended
+
#undef TARGET_MODES_TIEABLE_P
#define TARGET_MODES_TIEABLE_P riscv_modes_tieable_p
diff --git a/gcc/testsuite/gcc.target/riscv/shift-shift-2.c
b/gcc/testsuite/gcc.target/riscv/shift-shift-2.c
index 5f93be15ac5..2f38b3f0fec 100644
--- a/gcc/testsuite/gcc.target/riscv/shift-shift-2.c
+++ b/gcc/testsuite/gcc.target/riscv/shift-shift-2.c
@@ -38,5 +38,3 @@ sub5 (unsigned int i)
}
/* { dg-final { scan-assembler-times "slli" 5 } } */
/* { dg-final { scan-assembler-times "srli" 5 } } */
-/* { dg-final { scan-assembler-times "slliw" 1 } } */
-/* { dg-final { scan-assembler-times "srliw" 1 } } */
--
2.34.1
