[PATCH] Don't allow mask/sse/mmx mov in TLS code sequences.
Uros Bizjak
ubizjak@gmail.com
Fri Nov 19 07:50:23 GMT 2021
On Fri, Nov 19, 2021 at 2:14 AM liuhongt <hongtao.liu@intel.com> wrote:
>
> >Why is the above declared as a special memory constraint? Also the
> Change to define_memory_constraint since it's ok for
> reload can make them match by converting the operand to the form
> ‘(mem (reg X))’.where X is a base register (from the register class specified
> by BASE_REG_CLASS
>
> >predicate comment is missing and the description should say something
> >like:
> >
> >@internal TLS address that allows insn using non-integer registers
> Changed.
>
> >I think it is better to avoid negative logic. So, something like
> >
> >Return true if the TLS address requires insn using integer registers.
> >
> >bool
> >ix86_gpr_tls_address_pattern_p
> >
> >(and use not in the predicate)
>
> Changed.
>
> >> +{
> >> + gcc_assert (MEM_P (mem));
> >> +
> >> + rtx addr = XEXP (mem, 0);
> >> + subrtx_var_iterator::array_type array;
> >> + FOR_EACH_SUBRTX_VAR (iter, array, addr, ALL)
> >> + {
> >> + rtx op = *iter;
> >> + if (GET_CODE (op) == UNSPEC)
> >> + switch (XINT (op, 1))
> >> + {
> >> + case UNSPEC_GOTNTPOFF:
> >> + return false;
> >> + case UNSPEC_TPOFF:
> >> + if (!TARGET_64BIT)
> >> + return false;
> >> + break;
> >> + default:
> >> + break;
> >> + }
> >> + /* Should iter.skip_subrtxes ();
> >> + if there's no inner UNSPEC in addr???. */
>
> >You should figure the above before submitting the patch.
> ix86_print_operand_address_as shows there could be inner UNSPEC in addr, so
> remove comments.
>
> >Can you please minimize the testcase?
> Done;
>
> As change in assembler, refer to [1], this patch disallow mask/sse/mmx
> mov in TLS code sequences which require integer MOV instructions.
>
> [1] https://sourceware.org/git/?p=binutils-gdb.git;a=patch;h=d7e3e627027fcf37d63e284144fe27ff4eba36b5
>
> gcc/ChangeLog:
>
> PR target/103275
> * config/i386/i386-protos.h (ix86_gpr_tls_address_pattern_p):
> Declare.
> * config/i386/i386.c (ix86_gpr_tls_address_pattern_p): New
> function.
> * config/i386/i386.md (*movsi_internal): Don't allow
> mask/sse/mmx move in TLS code sequences.
> (*movdi_internal): Ditto.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/pr103275.c: New test.
OK, with a small comment adjustment below.
Thanks,
Uros.
> ---
> gcc/config/i386/constraints.md | 5 ++
> gcc/config/i386/i386-protos.h | 1 +
> gcc/config/i386/i386.c | 32 +++++++++
> gcc/config/i386/i386.md | 18 ++---
> gcc/testsuite/gcc.target/i386/pr103275.c | 83 ++++++++++++++++++++++++
> 5 files changed, 130 insertions(+), 9 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr103275.c
>
> diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
> index eaa582d2055..15c5950ee6f 100644
> --- a/gcc/config/i386/constraints.md
> +++ b/gcc/config/i386/constraints.md
> @@ -185,6 +185,11 @@ (define_special_memory_constraint "Bc"
> (and (match_operand 0 "memory_operand")
> (match_test "constant_address_p (XEXP (op, 0))")))
>
> +(define_memory_constraint "Bk"
> + "@internal TLS address that allows insn using non-integer registers."
> + (and (match_operand 0 "memory_operand")
> + (not (match_test "ix86_gpr_tls_address_pattern_p (op)"))))
> +
> (define_special_memory_constraint "Bn"
> "@internal Memory operand without REX prefix."
> (match_operand 0 "norex_memory_operand"))
> diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
> index 7782cf1163f..941e91636d8 100644
> --- a/gcc/config/i386/i386-protos.h
> +++ b/gcc/config/i386/i386-protos.h
> @@ -240,6 +240,7 @@ extern unsigned int ix86_get_callcvt (const_tree);
> #endif
>
> extern rtx ix86_tls_module_base (void);
> +extern bool ix86_gpr_tls_address_pattern_p (rtx);
> extern bool ix86_tls_address_pattern_p (rtx);
> extern rtx ix86_rewrite_tls_address (rtx);
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 42c47d2b12b..68079e4230e 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -11468,6 +11468,38 @@ legitimize_tls_address (rtx x, enum tls_model model, bool for_mov)
> return dest;
> }
>
> +/* Return true if the TLS address requires insn using integer registers.
> + NB: it's different from ix86_tls_address_pattern_p since it also matchs
> + gottpoff/gotntpoff.
The above NB comment is not needed, the fact is obvious from the code.
> + It's used to prevent KMOV/VMOV in TLS code sequences which require integer
> + MOV instructions, refer to PR103275. */
> +bool
> +ix86_gpr_tls_address_pattern_p (rtx mem)
> +{
> + gcc_assert (MEM_P (mem));
> +
> + rtx addr = XEXP (mem, 0);
> + subrtx_var_iterator::array_type array;
> + FOR_EACH_SUBRTX_VAR (iter, array, addr, ALL)
> + {
> + rtx op = *iter;
> + if (GET_CODE (op) == UNSPEC)
> + switch (XINT (op, 1))
> + {
> + case UNSPEC_GOTNTPOFF:
> + return true;
> + case UNSPEC_TPOFF:
> + if (!TARGET_64BIT)
> + return true;
> + break;
> + default:
> + break;
> + }
> + }
> +
> + return false;
> +}
> +
> /* Return true if OP refers to a TLS address. */
> bool
> ix86_tls_address_pattern_p (rtx op)
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> index 97325e38676..82b85b26059 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -2085,9 +2085,9 @@ (define_split
>
> (define_insn "*movdi_internal"
> [(set (match_operand:DI 0 "nonimmediate_operand"
> - "=r ,o ,r,r ,r,m ,*y,*y,?*y,?m,?r,?*y,*v,*v,*v,m ,m,?r ,?*Yd,?r,?*v,?*y,?*x,*k,*k ,*r,*m,*k")
> + "=r ,o ,r,r ,r,m ,*y,*y,?*y,?m,?r,?*y,*v,*v,*v,m ,m,?r ,?*Yd,?r,?*v,?*y,?*x,*k,*k,*k ,*r,*m,*k")
> (match_operand:DI 1 "general_operand"
> - "riFo,riF,Z,rem,i,re,C ,*y,m ,*y,*y,r ,C ,*v,m ,*v,v,*Yd,r ,*v,r ,*x ,*y ,*r,*km,*k,*k,CBC"))]
> + "riFo,riF,Z,rem,i,re,C ,*y,Bk ,*y,*y,r ,C ,*v,Bk,*v,v,*Yd,r ,*v,r ,*x ,*y ,*r,*k,*Bk,*k,*k,CBC"))]
> "!(MEM_P (operands[0]) && MEM_P (operands[1]))
> && ix86_hardreg_mov_ok (operands[0], operands[1])"
> {
> @@ -2149,7 +2149,7 @@ (define_insn "*movdi_internal"
> [(set (attr "isa")
> (cond [(eq_attr "alternative" "0,1,17,18")
> (const_string "nox64")
> - (eq_attr "alternative" "2,3,4,5,10,11,23,25")
> + (eq_attr "alternative" "2,3,4,5,10,11,23,26")
> (const_string "x64")
> (eq_attr "alternative" "19,20")
> (const_string "x64_sse2")
> @@ -2170,9 +2170,9 @@ (define_insn "*movdi_internal"
> (const_string "ssemov")
> (eq_attr "alternative" "21,22")
> (const_string "ssecvt")
> - (eq_attr "alternative" "23,24,25,26")
> + (eq_attr "alternative" "23,24,25,26,27")
> (const_string "mskmov")
> - (eq_attr "alternative" "27")
> + (eq_attr "alternative" "28")
> (const_string "msklog")
> (and (match_operand 0 "register_operand")
> (match_operand 1 "pic_32bit_operand"))
> @@ -2306,9 +2306,9 @@ (define_peephole2
>
> (define_insn "*movsi_internal"
> [(set (match_operand:SI 0 "nonimmediate_operand"
> - "=r,m ,*y,*y,?*y,?m,?r,?*y,*v,*v,*v,m ,?r,?*v,*k,*k ,*rm,*k")
> + "=r,m ,*y,*y,?*y,?m,?r,?*y,*v,*v,*v,m ,?r,?*v,*k,*k ,*k,*rm,*k")
> (match_operand:SI 1 "general_operand"
> - "g ,re,C ,*y,m ,*y,*y,r ,C ,*v,m ,*v,*v,r ,*r,*km,*k ,CBC"))]
> + "g ,re,C ,*y,Bk ,*y,*y,r ,C ,*v,Bk,*v,*v,r ,*r,*k, *Bk,*k ,CBC"))]
> "!(MEM_P (operands[0]) && MEM_P (operands[1]))
> && ix86_hardreg_mov_ok (operands[0], operands[1])"
> {
> @@ -2373,9 +2373,9 @@ (define_insn "*movsi_internal"
> (const_string "sselog1")
> (eq_attr "alternative" "9,10,11,12,13")
> (const_string "ssemov")
> - (eq_attr "alternative" "14,15,16")
> + (eq_attr "alternative" "14,15,16,17")
> (const_string "mskmov")
> - (eq_attr "alternative" "17")
> + (eq_attr "alternative" "18")
> (const_string "msklog")
> (and (match_operand 0 "register_operand")
> (match_operand 1 "pic_32bit_operand"))
> diff --git a/gcc/testsuite/gcc.target/i386/pr103275.c b/gcc/testsuite/gcc.target/i386/pr103275.c
> new file mode 100644
> index 00000000000..c93413f3cde
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr103275.c
> @@ -0,0 +1,83 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -march=tigerlake -fPIC" } */
> +/* { dg-final { scan-assembler-not {(?n)kmovd.*@gotntpoff} } } */
> +
> +typedef unsigned short uint16_t;
> +typedef int int32_t;
> +typedef unsigned int uint32_t;
> +typedef unsigned char uint8_t;
> +
> +typedef uint32_t in_addr_t;
> +struct in_addr { in_addr_t s_addr; };
> +
> +extern __thread const uint16_t * __libc_tsd_CTYPE_B __attribute__ ((tls_model ("initial-exec")));
> +extern __thread int __libc_errno __attribute__ ((tls_model ("initial-exec")));
> +
> +extern unsigned long strtoul (const char*, char**, int);
> +extern uint32_t __bswap_32 (in_addr_t);
> +int
> +inet_aton_end (const char *cp, struct in_addr *addr, const char **endp)
> +{
> + static const in_addr_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
> + in_addr_t val;
> + char c;
> + union iaddr
> + {
> + uint8_t bytes[4];
> + uint32_t word;
> + } res;
> + uint8_t *pp = res.bytes;
> + int digit;
> +
> + int saved_errno = __libc_errno;
> + __libc_errno = 0;
> + res.word = 0;
> + c = *cp;
> +
> + for (;;)
> + {
> + if (c < '0' || c > '9')
> + goto ret_0;
> + {
> + char *endp;
> + unsigned long ul = strtoul (cp, &endp, 0);
> + if (ul == 0x7fffffffL && __libc_errno == 34)
> + goto ret_0;
> + if (ul > 0xfffffffful)
> + goto ret_0;
> + val = ul;
> + digit = cp != endp;
> + cp = endp;
> + }
> + c = *cp;
> + if (c == '.')
> + {
> + if (pp > res.bytes + 2 || val > 0xff)
> + goto ret_0;
> + *pp++ = val;
> + c = *++cp;
> + }
> + else
> + break;
> + }
> +
> + if (!(__libc_tsd_CTYPE_B[(int)c] & 8192))
> + goto ret_0;
> +
> + if (!digit)
> + goto ret_0;
> +
> + if (val > max[pp - res.bytes])
> + goto ret_0;
> +
> + if (addr != 0)
> + addr->s_addr = res.word | __bswap_32 (val);
> + *endp = cp;
> +
> + __libc_errno = saved_errno;
> + return 1;
> +
> + ret_0:
> + __libc_errno = saved_errno;
> + return 0;
> +}
> --
> 2.18.1
>
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