On 12/20/23 05:32, Jun Sha (Joshua) wrote:
This patch adds th. prefix to all XTheadVector instructions by
implementing new assembly output functions.
gcc/ChangeLog:
* config/riscv/riscv-protos.h
(riscv_asm_output_opcode): New function.
* config/riscv/riscv.cc (riscv_asm_output_opcode): Likewise.
* config/riscv/riscv.h (ASM_OUTPUT_OPCODE): Likewise.
Co-authored-by: Jin Ma <ji...@linux.alibaba.com>
Co-authored-by: Xianmiao Qu <cooper...@linux.alibaba.com>
Co-authored-by: Christoph Müllner <christoph.muell...@vrull.eu>
---
gcc/config/riscv/riscv-protos.h | 1 +
gcc/config/riscv/riscv.cc | 26 +++++++++++++++++++
gcc/config/riscv/riscv.h | 4 +++
.../riscv/rvv/xtheadvector/prefix.c | 12 +++++++++
4 files changed, 43 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/xtheadvector/prefix.c
diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index eaee53ce94e..f0eee71a18a 100644
--- a/gcc/config/riscv/riscv-protos.h
+++ b/gcc/config/riscv/riscv-protos.h
@@ -101,6 +101,7 @@ struct riscv_address_info {
};
/* Routines implemented in riscv.cc. */
+extern void riscv_asm_output_opcode(FILE *asm_out_file, const char *p);
extern enum riscv_symbol_type riscv_classify_symbolic_expression (rtx);
extern bool riscv_symbolic_constant_p (rtx, enum riscv_symbol_type *);
extern int riscv_float_const_rtx_index_for_fli (rtx);
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 8ae65760b6e..d3010bed8d8 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -5595,6 +5595,32 @@ riscv_get_v_regno_alignment (machine_mode mode)
return lmul;
}
+void
+riscv_asm_output_opcode(FILE *asm_out_file, const char *p)
Needs a function comment. There's several examples in this file you can
use to see the style we commonly use. And a minor formatting nit,
always put a space between a function name and an open paren.
+{
+ if (!TARGET_XTHEADVECTOR)
+ return;
+
+ if (current_output_insn == NULL_RTX)
+ return;
+
+ /* We need to handle the 'vset' special case here since it cannot
+ be controlled by vector mode. */
+ if (!strncmp (p, "vset", 4))
+ {
+ fputs ("th.", asm_out_file);
+ return;
+ }
+
+ subrtx_iterator::array_type array;
+ FOR_EACH_SUBRTX (iter, array, PATTERN (current_output_insn), ALL)
+ if (*iter && riscv_v_ext_mode_p (GET_MODE (*iter)) && p[0] == 'v')
+ {
+ fputs ("th.", asm_out_file);
+ return;
+ }
+}
So rather than looking at the mode, would it make more sense to have an
attribute (or re-use an existing attribute) to identify which opcodes
are going to need prefixing? We've got access to the INSN via
current_output_insn. So we can lookup attributes trivially.
This is a question, not a demand -- I'm looking for a solution that's
going to be reliable with minimal effort going forward.
jeff
