* [PATCH] x86: drop bogus Tbyte
@ 2022-10-31 10:18 Jan Beulich
2022-10-31 16:31 ` H.J. Lu
0 siblings, 1 reply; 2+ messages in thread
From: Jan Beulich @ 2022-10-31 10:18 UTC (permalink / raw)
To: Binutils; +Cc: H.J. Lu
Prior to commit 1cb0ab18ad24 ("x86/Intel: restrict suffix derivation")
the Tbyte modifier on the FLDT and FSTPT templates was pointless, as
No_ldSuf would have prevented it being accepted. Due to the special
nature of LONG_DOUBLE_MNEM_SUFFIX said commit, however, has led to these
insns being accepted in Intel syntax mode even when "tbyte ptr" was
present. Restore original behavior by dropping Tbyte there. (Note that
these insns in principle should by marked AT&T syntax only, but since
they haven't been so far we probably shouldn't change that.)
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -599,7 +599,7 @@ fld, 0xdb, 5, CpuFP, Modrm|No_bSuf|No_wS
fild, 0xdf, 0, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
fild, 0xdf, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64, { Qword|Unspecified|BaseIndex }
fildll, 0xdf, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Unspecified|BaseIndex }
-fldt, 0xdb, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Tbyte|Unspecified|BaseIndex }
+fldt, 0xdb, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Unspecified|BaseIndex }
fbld, 0xdf, 4, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf, { Tbyte|Unspecified|BaseIndex }
// store (no pop)
@@ -617,7 +617,7 @@ fstp, 0xdb, 7, CpuFP, Modrm|No_bSuf|No_w
fistp, 0xdf, 3, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
fistp, 0xdf, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64, { Qword|Unspecified|BaseIndex }
fistpll, 0xdf, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Unspecified|BaseIndex }
-fstpt, 0xdb, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Tbyte|Unspecified|BaseIndex }
+fstpt, 0xdb, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Unspecified|BaseIndex }
fbstp, 0xdf, 6, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf, { Tbyte|Unspecified|BaseIndex }
// exchange %st<n> with %st0
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] x86: drop bogus Tbyte
2022-10-31 10:18 [PATCH] x86: drop bogus Tbyte Jan Beulich
@ 2022-10-31 16:31 ` H.J. Lu
0 siblings, 0 replies; 2+ messages in thread
From: H.J. Lu @ 2022-10-31 16:31 UTC (permalink / raw)
To: Jan Beulich; +Cc: Binutils
On Mon, Oct 31, 2022 at 3:18 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> Prior to commit 1cb0ab18ad24 ("x86/Intel: restrict suffix derivation")
> the Tbyte modifier on the FLDT and FSTPT templates was pointless, as
> No_ldSuf would have prevented it being accepted. Due to the special
> nature of LONG_DOUBLE_MNEM_SUFFIX said commit, however, has led to these
> insns being accepted in Intel syntax mode even when "tbyte ptr" was
> present. Restore original behavior by dropping Tbyte there. (Note that
> these insns in principle should by marked AT&T syntax only, but since
> they haven't been so far we probably shouldn't change that.)
>
> --- a/opcodes/i386-opc.tbl
> +++ b/opcodes/i386-opc.tbl
> @@ -599,7 +599,7 @@ fld, 0xdb, 5, CpuFP, Modrm|No_bSuf|No_wS
> fild, 0xdf, 0, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
> fild, 0xdf, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64, { Qword|Unspecified|BaseIndex }
> fildll, 0xdf, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Unspecified|BaseIndex }
> -fldt, 0xdb, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Tbyte|Unspecified|BaseIndex }
> +fldt, 0xdb, 5, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Unspecified|BaseIndex }
> fbld, 0xdf, 4, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf, { Tbyte|Unspecified|BaseIndex }
>
> // store (no pop)
> @@ -617,7 +617,7 @@ fstp, 0xdb, 7, CpuFP, Modrm|No_bSuf|No_w
> fistp, 0xdf, 3, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
> fistp, 0xdf, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64, { Qword|Unspecified|BaseIndex }
> fistpll, 0xdf, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Unspecified|BaseIndex }
> -fstpt, 0xdb, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Tbyte|Unspecified|BaseIndex }
> +fstpt, 0xdb, 7, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Unspecified|BaseIndex }
> fbstp, 0xdf, 6, CpuFP, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf, { Tbyte|Unspecified|BaseIndex }
>
> // exchange %st<n> with %st0
OK.
Thanks.
--
H.J.
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2022-10-31 16:31 ` H.J. Lu
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