Message ID | 7d3846877141b74d4042aec96b9147a7e9d7285c.1623941442.git.wschmidt@linux.ibm.com |
---|---|
State | New |
Headers | show |
Series | Replace the Power target-specific builtin machinery | expand |
On Thu, 2021-06-17 at 10:19 -0500, Bill Schmidt via Gcc-patches wrote: > 2021-03-05 Bill Schmidt <wschmidt@linux.ibm.com> > Hi, > gcc/ > * config/rs6000/rs6000-call.c (new_cpu_expand_builtin): > Implement. ok > --- > gcc/config/rs6000/rs6000-call.c | 100 ++++++++++++++++++++++++++++++++ > 1 file changed, 100 insertions(+) > > diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c > index 754cd46b1c1..ad3e6a4bbe5 100644 > --- a/gcc/config/rs6000/rs6000-call.c > +++ b/gcc/config/rs6000/rs6000-call.c > @@ -14604,6 +14604,106 @@ static rtx > new_cpu_expand_builtin (enum rs6000_gen_builtins fcode, > tree exp ATTRIBUTE_UNUSED, rtx target) > { > + /* __builtin_cpu_init () is a nop, so expand to nothing. */ > + if (fcode == RS6000_BIF_CPU_INIT) > + return const0_rtx; > + > + if (target == 0 || GET_MODE (target) != SImode) > + target = gen_reg_rtx (SImode); > + > +#ifdef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB > + tree arg = TREE_OPERAND (CALL_EXPR_ARG (exp, 0), 0); > + /* Target clones creates an ARRAY_REF instead of STRING_CST, convert it back > + to a STRING_CST. */ > + if (TREE_CODE (arg) == ARRAY_REF > + && TREE_CODE (TREE_OPERAND (arg, 0)) == STRING_CST > + && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST > + && compare_tree_int (TREE_OPERAND (arg, 1), 0) == 0) > + arg = TREE_OPERAND (arg, 0); > + > + if (TREE_CODE (arg) != STRING_CST) > + { > + error ("builtin %qs only accepts a string argument", > + rs6000_builtin_info_x[(size_t) fcode].bifname); > + return const0_rtx; > + } > + > + if (fcode == RS6000_BIF_CPU_IS) > + { > + const char *cpu = TREE_STRING_POINTER (arg); > + rtx cpuid = NULL_RTX; > + for (size_t i = 0; i < ARRAY_SIZE (cpu_is_info); i++) > + if (strcmp (cpu, cpu_is_info[i].cpu) == 0) > + { > + /* The CPUID value in the TCB is offset by _DL_FIRST_PLATFORM. */ > + cpuid = GEN_INT (cpu_is_info[i].cpuid + _DL_FIRST_PLATFORM); > + break; > + } ok > + if (cpuid == NULL_RTX) > + { > + /* Invalid CPU argument. */ > + error ("cpu %qs is an invalid argument to builtin %qs", > + cpu, rs6000_builtin_info_x[(size_t) fcode].bifname); > + return const0_rtx; > + } > + > + rtx platform = gen_reg_rtx (SImode); > + rtx tcbmem = gen_const_mem (SImode, > + gen_rtx_PLUS (Pmode, > + gen_rtx_REG (Pmode, TLS_REGNUM), > + GEN_INT (TCB_PLATFORM_OFFSET))); > + emit_move_insn (platform, tcbmem); > + emit_insn (gen_eqsi3 (target, platform, cpuid)); > + } > + else if (fcode == RS6000_BIF_CPU_SUPPORTS) > + { > + const char *hwcap = TREE_STRING_POINTER (arg); > + rtx mask = NULL_RTX; > + int hwcap_offset; > + for (size_t i = 0; i < ARRAY_SIZE (cpu_supports_info); i++) > + if (strcmp (hwcap, cpu_supports_info[i].hwcap) == 0) > + { > + mask = GEN_INT (cpu_supports_info[i].mask); > + hwcap_offset = TCB_HWCAP_OFFSET (cpu_supports_info[i].id); > + break; > + } > + if (mask == NULL_RTX) > + { > + /* Invalid HWCAP argument. */ > + error ("%s %qs is an invalid argument to builtin %qs", > + "hwcap", hwcap, > + rs6000_builtin_info_x[(size_t) fcode].bifname); > + return const0_rtx; > + } > + > + rtx tcb_hwcap = gen_reg_rtx (SImode); > + rtx tcbmem = gen_const_mem (SImode, > + gen_rtx_PLUS (Pmode, > + gen_rtx_REG (Pmode, TLS_REGNUM), > + GEN_INT (hwcap_offset))); > + emit_move_insn (tcb_hwcap, tcbmem); > + rtx scratch1 = gen_reg_rtx (SImode); > + emit_insn (gen_rtx_SET (scratch1, gen_rtx_AND (SImode, tcb_hwcap, mask))); > + rtx scratch2 = gen_reg_rtx (SImode); > + emit_insn (gen_eqsi3 (scratch2, scratch1, const0_rtx)); > + emit_insn (gen_rtx_SET (target, gen_rtx_XOR (SImode, scratch2, const1_rtx))); > + } > + else > + gcc_unreachable (); > + > + /* Record that we have expanded a CPU builtin, so that we can later > + emit a reference to the special symbol exported by LIBC to ensure we > + do not link against an old LIBC that doesn't support this feature. */ > + cpu_builtin_p = true; > + > +#else > + warning (0, "builtin %qs needs GLIBC (2.23 and newer) that exports hardware " > + "capability bits", rs6000_builtin_info_x[(size_t) fcode].bifname); > + This seems OK. It appears to comply with the documentation at least :-) "If GCC was configured to use a GLIBC before 2.23, the built-in function __builtin_cpu_is always returns a 0 and the compiler issues a warning." ok lgtm, thanks -Will > + /* For old LIBCs, always return FALSE. */ > + emit_move_insn (target, GEN_INT (0)); > +#endif /* TARGET_LIBC_PROVIDES_HWCAP_IN_TCB */ > + > return target; > } >
On Tue, Jul 27, 2021 at 04:06:39PM -0500, will schmidt wrote: > On Thu, 2021-06-17 at 10:19 -0500, Bill Schmidt via Gcc-patches wrote: > > +#else > > + warning (0, "builtin %qs needs GLIBC (2.23 and newer) that exports hardware " > > + "capability bits", rs6000_builtin_info_x[(size_t) fcode].bifname); > > + > > This seems OK. > It appears to comply with the documentation at least :-) > "If GCC was configured to use a GLIBC before 2.23, the built-in > function __builtin_cpu_is always returns a 0 and the compiler > issues a warning." Yup. And we still (have to) support older glibc versions, since various distros ship with something older (2.23 is only 5 years old). Segher
diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c index 754cd46b1c1..ad3e6a4bbe5 100644 --- a/gcc/config/rs6000/rs6000-call.c +++ b/gcc/config/rs6000/rs6000-call.c @@ -14604,6 +14604,106 @@ static rtx new_cpu_expand_builtin (enum rs6000_gen_builtins fcode, tree exp ATTRIBUTE_UNUSED, rtx target) { + /* __builtin_cpu_init () is a nop, so expand to nothing. */ + if (fcode == RS6000_BIF_CPU_INIT) + return const0_rtx; + + if (target == 0 || GET_MODE (target) != SImode) + target = gen_reg_rtx (SImode); + +#ifdef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB + tree arg = TREE_OPERAND (CALL_EXPR_ARG (exp, 0), 0); + /* Target clones creates an ARRAY_REF instead of STRING_CST, convert it back + to a STRING_CST. */ + if (TREE_CODE (arg) == ARRAY_REF + && TREE_CODE (TREE_OPERAND (arg, 0)) == STRING_CST + && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST + && compare_tree_int (TREE_OPERAND (arg, 1), 0) == 0) + arg = TREE_OPERAND (arg, 0); + + if (TREE_CODE (arg) != STRING_CST) + { + error ("builtin %qs only accepts a string argument", + rs6000_builtin_info_x[(size_t) fcode].bifname); + return const0_rtx; + } + + if (fcode == RS6000_BIF_CPU_IS) + { + const char *cpu = TREE_STRING_POINTER (arg); + rtx cpuid = NULL_RTX; + for (size_t i = 0; i < ARRAY_SIZE (cpu_is_info); i++) + if (strcmp (cpu, cpu_is_info[i].cpu) == 0) + { + /* The CPUID value in the TCB is offset by _DL_FIRST_PLATFORM. */ + cpuid = GEN_INT (cpu_is_info[i].cpuid + _DL_FIRST_PLATFORM); + break; + } + if (cpuid == NULL_RTX) + { + /* Invalid CPU argument. */ + error ("cpu %qs is an invalid argument to builtin %qs", + cpu, rs6000_builtin_info_x[(size_t) fcode].bifname); + return const0_rtx; + } + + rtx platform = gen_reg_rtx (SImode); + rtx tcbmem = gen_const_mem (SImode, + gen_rtx_PLUS (Pmode, + gen_rtx_REG (Pmode, TLS_REGNUM), + GEN_INT (TCB_PLATFORM_OFFSET))); + emit_move_insn (platform, tcbmem); + emit_insn (gen_eqsi3 (target, platform, cpuid)); + } + else if (fcode == RS6000_BIF_CPU_SUPPORTS) + { + const char *hwcap = TREE_STRING_POINTER (arg); + rtx mask = NULL_RTX; + int hwcap_offset; + for (size_t i = 0; i < ARRAY_SIZE (cpu_supports_info); i++) + if (strcmp (hwcap, cpu_supports_info[i].hwcap) == 0) + { + mask = GEN_INT (cpu_supports_info[i].mask); + hwcap_offset = TCB_HWCAP_OFFSET (cpu_supports_info[i].id); + break; + } + if (mask == NULL_RTX) + { + /* Invalid HWCAP argument. */ + error ("%s %qs is an invalid argument to builtin %qs", + "hwcap", hwcap, + rs6000_builtin_info_x[(size_t) fcode].bifname); + return const0_rtx; + } + + rtx tcb_hwcap = gen_reg_rtx (SImode); + rtx tcbmem = gen_const_mem (SImode, + gen_rtx_PLUS (Pmode, + gen_rtx_REG (Pmode, TLS_REGNUM), + GEN_INT (hwcap_offset))); + emit_move_insn (tcb_hwcap, tcbmem); + rtx scratch1 = gen_reg_rtx (SImode); + emit_insn (gen_rtx_SET (scratch1, gen_rtx_AND (SImode, tcb_hwcap, mask))); + rtx scratch2 = gen_reg_rtx (SImode); + emit_insn (gen_eqsi3 (scratch2, scratch1, const0_rtx)); + emit_insn (gen_rtx_SET (target, gen_rtx_XOR (SImode, scratch2, const1_rtx))); + } + else + gcc_unreachable (); + + /* Record that we have expanded a CPU builtin, so that we can later + emit a reference to the special symbol exported by LIBC to ensure we + do not link against an old LIBC that doesn't support this feature. */ + cpu_builtin_p = true; + +#else + warning (0, "builtin %qs needs GLIBC (2.23 and newer) that exports hardware " + "capability bits", rs6000_builtin_info_x[(size_t) fcode].bifname); + + /* For old LIBCs, always return FALSE. */ + emit_move_insn (target, GEN_INT (0)); +#endif /* TARGET_LIBC_PROVIDES_HWCAP_IN_TCB */ + return target; }