[v2] RISC-V: make C-extension JAL available again for (32-bit) assembly
Checks
Commit Message
Along with the normal JAL alias, the C-extension one should have been
moved as well by 839189bc932e ("RISC-V: re-arrange opcode table for
consistent alias handling"), for the assembler to actually be able to
use it where/when possible.
Since neither this nor any other compressed branch insn was being tested
so far, take the opportunity and introduce a new testcase covering those.
---
Pretty clearly this should also go on the 2.40 branch.
---
v2: Avoid re-introducing PR/gas 29940.
Comments
Thanks for helping to follow these. Looks reasonable, so please commit.
Nelson
On Mon, Jan 30, 2023 at 10:07 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> Along with the normal JAL alias, the C-extension one should have been
> moved as well by 839189bc932e ("RISC-V: re-arrange opcode table for
> consistent alias handling"), for the assembler to actually be able to
> use it where/when possible.
>
> Since neither this nor any other compressed branch insn was being tested
> so far, take the opportunity and introduce a new testcase covering those.
> ---
> Pretty clearly this should also go on the 2.40 branch.
> ---
> v2: Avoid re-introducing PR/gas 29940.
>
> --- a/gas/config/tc-riscv.c
> +++ b/gas/config/tc-riscv.c
> @@ -2764,6 +2764,8 @@ riscv_ip (char *str, struct riscv_cl_ins
> case 'p':
> goto branch;
> case 'a':
> + if (oparg == insn->args + 1)
> + goto jump_check_gpr;
> goto jump;
> case 'S': /* Floating-point RS1 x8-x15. */
> if (!reg_lookup (&asarg, RCLASS_FPR, ®no)
> @@ -3273,6 +3275,7 @@ riscv_ip (char *str, struct riscv_cl_ins
> but the 2nd (with 2 operands) might. */
> if (oparg == insn->args)
> {
> + jump_check_gpr:
> asargStart = asarg;
> if (reg_lookup (&asarg, RCLASS_GPR, NULL)
> && (*asarg == ',' || (ISSPACE (*asarg) && asarg[1] == ',')))
> --- a/opcodes/riscv-opc.c
> +++ b/opcodes/riscv-opc.c
> @@ -340,9 +340,9 @@ const struct riscv_opcode riscv_opcodes[
> {"jalr", 0, INSN_CLASS_I, "d,s,j", MATCH_JALR, MASK_JALR, match_opcode, INSN_JSR },
> {"j", 0, INSN_CLASS_C, "Ca", MATCH_C_J, MASK_C_J, match_opcode, INSN_ALIAS|INSN_BRANCH },
> {"j", 0, INSN_CLASS_I, "a", MATCH_JAL, MASK_JAL|MASK_RD, match_opcode, INSN_ALIAS|INSN_BRANCH },
> +{"jal", 32, INSN_CLASS_C, "Ca", MATCH_C_JAL, MASK_C_JAL, match_opcode, INSN_ALIAS|INSN_JSR },
> {"jal", 0, INSN_CLASS_I, "a", MATCH_JAL|(X_RA << OP_SH_RD), MASK_JAL|MASK_RD, match_opcode, INSN_ALIAS|INSN_JSR },
> {"jal", 0, INSN_CLASS_I, "d,a", MATCH_JAL, MASK_JAL, match_opcode, INSN_JSR },
> -{"jal", 32, INSN_CLASS_C, "Ca", MATCH_C_JAL, MASK_C_JAL, match_opcode, INSN_ALIAS|INSN_JSR },
> {"call", 0, INSN_CLASS_I, "d,c", (X_T1 << OP_SH_RS1), (int) M_CALL, match_never, INSN_MACRO },
> {"call", 0, INSN_CLASS_I, "c", (X_RA << OP_SH_RS1)|(X_RA << OP_SH_RD), (int) M_CALL, match_never, INSN_MACRO },
> {"tail", 0, INSN_CLASS_I, "c", (X_T1 << OP_SH_RS1), (int) M_CALL, match_never, INSN_MACRO },
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/c-branch-na.d
> @@ -0,0 +1,20 @@
> +#as: -march=rv32ic
> +#source: c-branch.s
> +#objdump: -drw -Mno-aliases
> +
> +.*:[ ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0+ <target>:
> +[ ]+[0-9a-f]+:[ ]+c001[ ]+c\.beqz[ ]+s0,0 <target>[ ]+0: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+dcfd[ ]+c\.beqz[ ]+s1,0 <target>[ ]+2: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+fc75[ ]+c\.bnez[ ]+s0,0 <target>[ ]+4: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+fced[ ]+c\.bnez[ ]+s1,0 <target>[ ]+6: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+bfe5[ ]+c\.j[ ]+0 <target>[ ]+8: R_RISCV_RVC_JUMP .*
> +[ ]+[0-9a-f]+:[ ]+3fdd[ ]+c\.jal[ ]+0 <target>[ ]+a: R_RISCV_RVC_JUMP .*
> +[ ]+[0-9a-f]+:[ ]+9302[ ]+c\.jalr[ ]+t1
> +[ ]+[0-9a-f]+:[ ]+8382[ ]+c\.jr[ ]+t2
> +[ ]+[0-9a-f]+:[ ]+8082[ ]+c\.jr[ ]+ra
> +#...
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/c-branch.d
> @@ -0,0 +1,19 @@
> +#as: -march=rv64ic
> +#objdump: -drw
> +
> +.*:[ ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0+ <target>:
> +[ ]+[0-9a-f]+:[ ]+c001[ ]+beqz[ ]+s0,0 <target>[ ]+0: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+dcfd[ ]+beqz[ ]+s1,0 <target>[ ]+2: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+fc75[ ]+bnez[ ]+s0,0 <target>[ ]+4: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+fced[ ]+bnez[ ]+s1,0 <target>[ ]+6: R_RISCV_RVC_BRANCH .*
> +[ ]+[0-9a-f]+:[ ]+bfe5[ ]+j[ ]+0 <target>[ ]+8: R_RISCV_RVC_JUMP .*
> +[ ]+[0-9a-f]+:[ ]+ff7ff0ef[ ]+jal[ ]+0 <target>[ ]+a: R_RISCV_JAL .*
> +[ ]+[0-9a-f]+:[ ]+9302[ ]+jalr[ ]+t1
> +[ ]+[0-9a-f]+:[ ]+8382[ ]+jr[ ]+t2
> +[ ]+[0-9a-f]+:[ ]+8082[ ]+ret
> +#...
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/c-branch.s
> @@ -0,0 +1,11 @@
> + .text
> +target:
> + beq x8, x0, target
> + beqz x9, target
> + bne x8, x0, target
> + bnez x9, target
> + j target
> + jal target
> + jalr x6
> + jr x7
> + ret
On 31.01.2023 02:11, Nelson Chu wrote:
> Thanks for helping to follow these.
Well, it was my fault.
> Looks reasonable, so please commit.
Done, also ..
> On Mon, Jan 30, 2023 at 10:07 PM Jan Beulich <jbeulich@suse.com> wrote:
>>
>> Along with the normal JAL alias, the C-extension one should have been
>> moved as well by 839189bc932e ("RISC-V: re-arrange opcode table for
>> consistent alias handling"), for the assembler to actually be able to
>> use it where/when possible.
>>
>> Since neither this nor any other compressed branch insn was being tested
>> so far, take the opportunity and introduce a new testcase covering those.
>> ---
>> Pretty clearly this should also go on the 2.40 branch.
... on to the branch.
>> --- a/gas/config/tc-riscv.c
>> +++ b/gas/config/tc-riscv.c
>> @@ -2764,6 +2764,8 @@ riscv_ip (char *str, struct riscv_cl_ins
>> case 'p':
>> goto branch;
>> case 'a':
>> + if (oparg == insn->args + 1)
>> + goto jump_check_gpr;
>> goto jump;
>> case 'S': /* Floating-point RS1 x8-x15. */
>> if (!reg_lookup (&asarg, RCLASS_FPR, ®no)
>> @@ -3273,6 +3275,7 @@ riscv_ip (char *str, struct riscv_cl_ins
>> but the 2nd (with 2 operands) might. */
>> if (oparg == insn->args)
>> {
>> + jump_check_gpr:
>> asargStart = asarg;
>> if (reg_lookup (&asarg, RCLASS_GPR, NULL)
>> && (*asarg == ',' || (ISSPACE (*asarg) && asarg[1] == ',')))
Just to mention it: I already have a patch to remove all this hackery
again, I just want to chew on it for a little more before posting, in
case I notice something that's wrong with the approach taken.
Jan
@@ -2764,6 +2764,8 @@ riscv_ip (char *str, struct riscv_cl_ins
case 'p':
goto branch;
case 'a':
+ if (oparg == insn->args + 1)
+ goto jump_check_gpr;
goto jump;
case 'S': /* Floating-point RS1 x8-x15. */
if (!reg_lookup (&asarg, RCLASS_FPR, ®no)
@@ -3273,6 +3275,7 @@ riscv_ip (char *str, struct riscv_cl_ins
but the 2nd (with 2 operands) might. */
if (oparg == insn->args)
{
+ jump_check_gpr:
asargStart = asarg;
if (reg_lookup (&asarg, RCLASS_GPR, NULL)
&& (*asarg == ',' || (ISSPACE (*asarg) && asarg[1] == ',')))
@@ -340,9 +340,9 @@ const struct riscv_opcode riscv_opcodes[
{"jalr", 0, INSN_CLASS_I, "d,s,j", MATCH_JALR, MASK_JALR, match_opcode, INSN_JSR },
{"j", 0, INSN_CLASS_C, "Ca", MATCH_C_J, MASK_C_J, match_opcode, INSN_ALIAS|INSN_BRANCH },
{"j", 0, INSN_CLASS_I, "a", MATCH_JAL, MASK_JAL|MASK_RD, match_opcode, INSN_ALIAS|INSN_BRANCH },
+{"jal", 32, INSN_CLASS_C, "Ca", MATCH_C_JAL, MASK_C_JAL, match_opcode, INSN_ALIAS|INSN_JSR },
{"jal", 0, INSN_CLASS_I, "a", MATCH_JAL|(X_RA << OP_SH_RD), MASK_JAL|MASK_RD, match_opcode, INSN_ALIAS|INSN_JSR },
{"jal", 0, INSN_CLASS_I, "d,a", MATCH_JAL, MASK_JAL, match_opcode, INSN_JSR },
-{"jal", 32, INSN_CLASS_C, "Ca", MATCH_C_JAL, MASK_C_JAL, match_opcode, INSN_ALIAS|INSN_JSR },
{"call", 0, INSN_CLASS_I, "d,c", (X_T1 << OP_SH_RS1), (int) M_CALL, match_never, INSN_MACRO },
{"call", 0, INSN_CLASS_I, "c", (X_RA << OP_SH_RS1)|(X_RA << OP_SH_RD), (int) M_CALL, match_never, INSN_MACRO },
{"tail", 0, INSN_CLASS_I, "c", (X_T1 << OP_SH_RS1), (int) M_CALL, match_never, INSN_MACRO },
@@ -0,0 +1,20 @@
+#as: -march=rv32ic
+#source: c-branch.s
+#objdump: -drw -Mno-aliases
+
+.*:[ ]+file format .*
+
+
+Disassembly of section .text:
+
+0+ <target>:
+[ ]+[0-9a-f]+:[ ]+c001[ ]+c\.beqz[ ]+s0,0 <target>[ ]+0: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+dcfd[ ]+c\.beqz[ ]+s1,0 <target>[ ]+2: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+fc75[ ]+c\.bnez[ ]+s0,0 <target>[ ]+4: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+fced[ ]+c\.bnez[ ]+s1,0 <target>[ ]+6: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+bfe5[ ]+c\.j[ ]+0 <target>[ ]+8: R_RISCV_RVC_JUMP .*
+[ ]+[0-9a-f]+:[ ]+3fdd[ ]+c\.jal[ ]+0 <target>[ ]+a: R_RISCV_RVC_JUMP .*
+[ ]+[0-9a-f]+:[ ]+9302[ ]+c\.jalr[ ]+t1
+[ ]+[0-9a-f]+:[ ]+8382[ ]+c\.jr[ ]+t2
+[ ]+[0-9a-f]+:[ ]+8082[ ]+c\.jr[ ]+ra
+#...
@@ -0,0 +1,19 @@
+#as: -march=rv64ic
+#objdump: -drw
+
+.*:[ ]+file format .*
+
+
+Disassembly of section .text:
+
+0+ <target>:
+[ ]+[0-9a-f]+:[ ]+c001[ ]+beqz[ ]+s0,0 <target>[ ]+0: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+dcfd[ ]+beqz[ ]+s1,0 <target>[ ]+2: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+fc75[ ]+bnez[ ]+s0,0 <target>[ ]+4: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+fced[ ]+bnez[ ]+s1,0 <target>[ ]+6: R_RISCV_RVC_BRANCH .*
+[ ]+[0-9a-f]+:[ ]+bfe5[ ]+j[ ]+0 <target>[ ]+8: R_RISCV_RVC_JUMP .*
+[ ]+[0-9a-f]+:[ ]+ff7ff0ef[ ]+jal[ ]+0 <target>[ ]+a: R_RISCV_JAL .*
+[ ]+[0-9a-f]+:[ ]+9302[ ]+jalr[ ]+t1
+[ ]+[0-9a-f]+:[ ]+8382[ ]+jr[ ]+t2
+[ ]+[0-9a-f]+:[ ]+8082[ ]+ret
+#...
@@ -0,0 +1,11 @@
+ .text
+target:
+ beq x8, x0, target
+ beqz x9, target
+ bne x8, x0, target
+ bnez x9, target
+ j target
+ jal target
+ jalr x6
+ jr x7
+ ret