* [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi
@ 2023-02-28 5:00 Lin Sinan
2023-02-28 5:12 ` Sinan Lin
2023-02-28 9:32 ` Philipp Tomsich
0 siblings, 2 replies; 4+ messages in thread
From: Lin Sinan @ 2023-02-28 5:00 UTC (permalink / raw)
To: gcc-patches; +Cc: philipp.tomsich, kito.cheng, palmer, andrew, Lin Sinan
From: Lin Sinan <sinan.lin@linux.alibaba.com>
The partial subreg check should be for subreg operand(operand 1) instead of
the immediate operand(operand 2). This change also fix pr68648.c in zbs.
gcc/ChangeLog:
* config/riscv/bitmanip.md: Fix wrong index in the check.
---
gcc/config/riscv/bitmanip.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/config/riscv/bitmanip.md b/gcc/config/riscv/bitmanip.md
index 14d18edbe62..58a86bd929f 100644
--- a/gcc/config/riscv/bitmanip.md
+++ b/gcc/config/riscv/bitmanip.md
@@ -442,7 +442,7 @@
(ior:DI (sign_extend:DI (match_operand:SI 1 "register_operand" "r"))
(match_operand 2 "single_bit_mask_operand" "i")))]
"TARGET_ZBS && TARGET_64BIT
- && !partial_subreg_p (operands[2])"
+ && !partial_subreg_p (operands[1])"
"bseti\t%0,%1,%S2"
[(set_attr "type" "bitmanip")])
--
2.34.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi
2023-02-28 5:00 [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi Lin Sinan
@ 2023-02-28 5:12 ` Sinan Lin
2023-02-28 9:32 ` Philipp Tomsich
1 sibling, 0 replies; 4+ messages in thread
From: Sinan Lin @ 2023-02-28 5:12 UTC (permalink / raw)
To: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 2398 bytes --]
I encountered a miscompilation case with zbs, where bseti without sign
extension emitted from bsetidisi pattern leads to wrong output.
Take pr68648.c as an example, -march=rv64gc_zba_zbb_zbs -O3 did not generate
sext.w in int bar (void) and led to a wrong value in a0. It seems that the
partial subreg
check is wrongly set to the immediate operand.
int foo (void):
li a0,123
ret
int bar (void):
addi sp,sp,-16
sd ra,8(sp)
call foo # a0 123
li a5,248639488 # a0 123, a5 0xed1f000
addi a5,a5,11 # a0 123, a5 0xed1f00b
slli a5,a5,14 # a0 123, a5 0x3b47c02c000
addi a5,a5,-8 # a0 123, a5 0x3b47c02bff8
ld ra,8(sp)
or a0,a0,a5 # a0 0x3b47c02bffb, a5 0x3b47c02bff8
bseti a5,zero,32 # a0 0x3b47c02bffb, a5 0x100000000
addi a5,a5,-1 # a0 0x3b47c02bffb, a5 0x0ffffffff
xor a0,a0,a5 # a0 0x3b483fd4004, a5 0x0ffffffff
bseti a0,a0,0 # a0 0x3b483fd4005, a5 0x0ffffffff
addi sp,sp,16 # sext.w a0,a0 is missing
jr ra
main:
addi sp,sp,-16
sd ra,8(sp)
call bar
li a5,-2080555008
addi a5,a5,5
bne a0,a5,.L8 # a0 0x3b483fd4005, a5 0x83fd4005
ld ra,8(sp)
li a0,0
addi sp,sp,16
jr ra
.L8:
call abort
Lin Sinan <mynameisxiaou@gmail.com> 于2023年2月28日周二 13:00写道：
> From: Lin Sinan <sinan.lin@linux.alibaba.com>
>
> The partial subreg check should be for subreg operand(operand 1) instead of
> the immediate operand(operand 2). This change also fix pr68648.c in zbs.
>
> gcc/ChangeLog:
>
> * config/riscv/bitmanip.md: Fix wrong index in the check.
>
> ---
> gcc/config/riscv/bitmanip.md | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/config/riscv/bitmanip.md b/gcc/config/riscv/bitmanip.md
> index 14d18edbe62..58a86bd929f 100644
> --- a/gcc/config/riscv/bitmanip.md
> +++ b/gcc/config/riscv/bitmanip.md
> @@ -442,7 +442,7 @@
> (ior:DI (sign_extend:DI (match_operand:SI 1 "register_operand"
> "r"))
> (match_operand 2 "single_bit_mask_operand" "i")))]
> "TARGET_ZBS && TARGET_64BIT
> - && !partial_subreg_p (operands[2])"
> + && !partial_subreg_p (operands[1])"
> "bseti\t%0,%1,%S2"
> [(set_attr "type" "bitmanip")])
>
> --
> 2.34.1
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi
2023-02-28 5:00 [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi Lin Sinan
2023-02-28 5:12 ` Sinan Lin
@ 2023-02-28 9:32 ` Philipp Tomsich
2023-03-05 9:27 ` Kito Cheng
1 sibling, 1 reply; 4+ messages in thread
From: Philipp Tomsich @ 2023-02-28 9:32 UTC (permalink / raw)
To: Lin Sinan; +Cc: gcc-patches, kito.cheng, palmer, andrew, Lin Sinan
On Tue, 28 Feb 2023 at 06:00, Lin Sinan <mynameisxiaou@gmail.com> wrote:
>
> From: Lin Sinan <sinan.lin@linux.alibaba.com>
>
> The partial subreg check should be for subreg operand(operand 1) instead of
> the immediate operand(operand 2). This change also fix pr68648.c in zbs.
Good catch.
Reviewed-by: <philipp.tomsich@vrull.eu>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi
2023-02-28 9:32 ` Philipp Tomsich
@ 2023-03-05 9:27 ` Kito Cheng
0 siblings, 0 replies; 4+ messages in thread
From: Kito Cheng @ 2023-03-05 9:27 UTC (permalink / raw)
To: Philipp Tomsich; +Cc: Lin Sinan, gcc-patches, palmer, andrew, Lin Sinan
Committed, thanks!
On Tue, Feb 28, 2023 at 5:32 PM Philipp Tomsich
<philipp.tomsich@vrull.eu> wrote:
>
> On Tue, 28 Feb 2023 at 06:00, Lin Sinan <mynameisxiaou@gmail.com> wrote:
> >
> > From: Lin Sinan <sinan.lin@linux.alibaba.com>
> >
> > The partial subreg check should be for subreg operand(operand 1) instead of
> > the immediate operand(operand 2). This change also fix pr68648.c in zbs.
>
> Good catch.
> Reviewed-by: <philipp.tomsich@vrull.eu>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-02-28 5:00 [PATCH] RISC-V: Fix wrong partial subreg check for bsetidisi Lin Sinan
2023-02-28 5:12 ` Sinan Lin
2023-02-28 9:32 ` Philipp Tomsich
2023-03-05 9:27 ` Kito Cheng
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