gcc/ChangeLog: * config/i386/i386-modes.def (FLOAT_MODE): Define ieee HFmode. * config/i386/i386.c (enum x86_64_reg_class): Add X86_64_SSEHF_CLASS. (merge_classes): Handle X86_64_SSEHF_CLASS. (examine_argument): Ditto. (construct_container): Ditto. (classify_argument): Ditto, and set HFmode/HCmode to X86_64_SSEHF_CLASS. (function_value_32): Return _FLoat16/Complex Float16 by %xmm0/%xmm1. (function_value_64): Return _Float16/Complex Float16 by SSE register. (ix86_print_operand): Handle CONST_DOUBLE HFmode. (ix86_secondary_reload): Require gpr as intermediate register to store _Float16 from sse register when sse4 is not available. (ix86_hard_regno_mode_ok): Put HFmode in sse register and gpr. (ix86_libgcc_floating_mode_supported_p): Enable _FLoat16 under sse2. (ix86_scalar_mode_supported_p): Ditto. (TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P): Defined. (ix86_get_excess_precision): Return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16 under sse2. * config/i386/i386.h (VALID_SSE2_REG_MODE): Add HFmode. * config/i386/i386.md (*pushhf_rex64): New define_insn. (*pushhf): Ditto. (*movhf_internal): Ditto. * doc/extend.texi (Half-Precision Floating Point): Documemt _Float16 for x86.
gcc/lto/ChangeLog: * lto-lang.c (lto_type_for_mode): Return float16_type_node when mode == TYPE_MODE (float16_type_node). gcc/testsuite/ChangeLog * gcc.target/i386/sse2-float16-1.c: New test. * gcc.target/i386/sse2-float16-2.c: Ditto. * gcc.target/i386/sse2-float16-3.c: Ditto. --- gcc/config/i386/i386-modes.def | 1 + gcc/config/i386/i386.c | 99 ++++++++++++++- gcc/config/i386/i386.h | 2 +- gcc/config/i386/i386.md | 118 +++++++++++++++++- gcc/doc/extend.texi | 16 +++ gcc/lto/lto-lang.c | 3 + .../gcc.target/i386/sse2-float16-1.c | 8 ++ .../gcc.target/i386/sse2-float16-2.c | 16 +++ .../gcc.target/i386/sse2-float16-3.c | 12 ++ 9 files changed, 265 insertions(+), 10 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/sse2-float16-1.c create mode 100644 gcc/testsuite/gcc.target/i386/sse2-float16-2.c create mode 100644 gcc/testsuite/gcc.target/i386/sse2-float16-3.c diff --git a/gcc/config/i386/i386-modes.def b/gcc/config/i386/i386-modes.def index 4e7014be034..9232f59a925 100644 --- a/gcc/config/i386/i386-modes.def +++ b/gcc/config/i386/i386-modes.def @@ -23,6 +23,7 @@ along with GCC; see the file COPYING3. If not see FRACTIONAL_FLOAT_MODE (XF, 80, 12, ieee_extended_intel_96_format); FLOAT_MODE (TF, 16, ieee_quad_format); +FLOAT_MODE (HF, 2, ieee_half_format); /* In ILP32 mode, XFmode has size 12 and alignment 4. In LP64 mode, XFmode has size and alignment 16. */ diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index ff96134fb37..02628d838fc 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -387,6 +387,7 @@ enum x86_64_reg_class X86_64_INTEGER_CLASS, X86_64_INTEGERSI_CLASS, X86_64_SSE_CLASS, + X86_64_SSEHF_CLASS, X86_64_SSESF_CLASS, X86_64_SSEDF_CLASS, X86_64_SSEUP_CLASS, @@ -2023,8 +2024,10 @@ merge_classes (enum x86_64_reg_class class1, enum x86_64_reg_class class2) return X86_64_MEMORY_CLASS; /* Rule #4: If one of the classes is INTEGER, the result is INTEGER. */ - if ((class1 == X86_64_INTEGERSI_CLASS && class2 == X86_64_SSESF_CLASS) - || (class2 == X86_64_INTEGERSI_CLASS && class1 == X86_64_SSESF_CLASS)) + if ((class1 == X86_64_INTEGERSI_CLASS + && (class2 == X86_64_SSESF_CLASS || class2 == X86_64_SSEHF_CLASS)) + || (class2 == X86_64_INTEGERSI_CLASS + && (class1 == X86_64_SSESF_CLASS || class1 == X86_64_SSEHF_CLASS))) return X86_64_INTEGERSI_CLASS; if (class1 == X86_64_INTEGER_CLASS || class1 == X86_64_INTEGERSI_CLASS || class2 == X86_64_INTEGER_CLASS || class2 == X86_64_INTEGERSI_CLASS) @@ -2178,6 +2181,8 @@ classify_argument (machine_mode mode, const_tree type, /* The partial classes are now full classes. */ if (subclasses[0] == X86_64_SSESF_CLASS && bytes != 4) subclasses[0] = X86_64_SSE_CLASS; + if (subclasses[0] == X86_64_SSEHF_CLASS && bytes != 2) + subclasses[0] = X86_64_SSE_CLASS; if (subclasses[0] == X86_64_INTEGERSI_CLASS && !((bit_offset % 64) == 0 && bytes == 4)) subclasses[0] = X86_64_INTEGER_CLASS; @@ -2350,6 +2355,12 @@ classify_argument (machine_mode mode, const_tree type, gcc_unreachable (); case E_CTImode: return 0; + case E_HFmode: + if (!(bit_offset % 64)) + classes[0] = X86_64_SSEHF_CLASS; + else + classes[0] = X86_64_SSE_CLASS; + return 1; case E_SFmode: if (!(bit_offset % 64)) classes[0] = X86_64_SSESF_CLASS; @@ -2367,6 +2378,15 @@ classify_argument (machine_mode mode, const_tree type, classes[0] = X86_64_SSE_CLASS; classes[1] = X86_64_SSEUP_CLASS; return 2; + case E_HCmode: + classes[0] = X86_64_SSE_CLASS; + if (!(bit_offset % 64)) + return 1; + else + { + classes[1] = X86_64_SSEHF_CLASS; + return 2; + } case E_SCmode: classes[0] = X86_64_SSE_CLASS; if (!(bit_offset % 64)) @@ -2481,6 +2501,7 @@ examine_argument (machine_mode mode, const_tree type, int in_return, (*int_nregs)++; break; case X86_64_SSE_CLASS: + case X86_64_SSEHF_CLASS: case X86_64_SSESF_CLASS: case X86_64_SSEDF_CLASS: (*sse_nregs)++; @@ -2580,13 +2601,14 @@ construct_container (machine_mode mode, machine_mode orig_mode, /* First construct simple cases. Avoid SCmode, since we want to use single register to pass this type. */ - if (n == 1 && mode != SCmode) + if (n == 1 && mode != SCmode && mode != HCmode) switch (regclass[0]) { case X86_64_INTEGER_CLASS: case X86_64_INTEGERSI_CLASS: return gen_rtx_REG (mode, intreg[0]); case X86_64_SSE_CLASS: + case X86_64_SSEHF_CLASS: case X86_64_SSESF_CLASS: case X86_64_SSEDF_CLASS: if (mode != BLKmode) @@ -2683,6 +2705,14 @@ construct_container (machine_mode mode, machine_mode orig_mode, GEN_INT (i*8)); intreg++; break; + case X86_64_SSEHF_CLASS: + exp [nexps++] + = gen_rtx_EXPR_LIST (VOIDmode, + gen_rtx_REG (HFmode, + GET_SSE_REGNO (sse_regno)), + GEN_INT (i*8)); + sse_regno++; + break; case X86_64_SSESF_CLASS: exp [nexps++] = gen_rtx_EXPR_LIST (VOIDmode, @@ -3903,6 +3933,19 @@ function_value_32 (machine_mode orig_mode, machine_mode mode, /* Most things go in %eax. */ regno = AX_REG; + /* Return _Float16/_Complex _Foat16 by sse register. */ + if (mode == HFmode) + regno = FIRST_SSE_REG; + if (mode == HCmode) + { + rtx ret = gen_rtx_PARALLEL (mode, rtvec_alloc(1)); + XVECEXP (ret, 0, 0) + = gen_rtx_EXPR_LIST (VOIDmode, + gen_rtx_REG (SImode, FIRST_SSE_REG), + GEN_INT (0)); + return ret; + } + /* Override FP return register with %xmm0 for local functions when SSE math is enabled or for functions with sseregparm attribute. */ if ((fn || fntype) && (mode == SFmode || mode == DFmode)) @@ -3939,6 +3982,8 @@ function_value_64 (machine_mode orig_mode, machine_mode mode, switch (mode) { + case E_HFmode: + case E_HCmode: case E_SFmode: case E_SCmode: case E_DFmode: @@ -13411,6 +13456,15 @@ ix86_print_operand (FILE *file, rtx x, int code) (file, addr, MEM_ADDR_SPACE (x), code == 'p' || code == 'P'); } + else if (CONST_DOUBLE_P (x) && GET_MODE (x) == HFmode) + { + long l = real_to_target (NULL, CONST_DOUBLE_REAL_VALUE (x), + REAL_MODE_FORMAT (HFmode)); + if (ASSEMBLER_DIALECT == ASM_ATT) + putc ('$', file); + fprintf (file, "0x%04x", (unsigned int) l); + } + else if (CONST_DOUBLE_P (x) && GET_MODE (x) == SFmode) { long l; @@ -18928,6 +18982,16 @@ ix86_secondary_reload (bool in_p, rtx x, reg_class_t rclass, return NO_REGS; } + /* Require movement to gpr, and then store to memory. */ + if (mode == HFmode + && !TARGET_SSE4_1 + && SSE_CLASS_P (rclass) + && !in_p && MEM_P (x)) + { + sri->extra_cost = 1; + return GENERAL_REGS; + } + /* This condition handles corner case where an expression involving pointers gets vectorized. We're trying to use the address of a stack slot as a vector initializer. @@ -19546,6 +19610,8 @@ ix86_hard_regno_mode_ok (unsigned int regno, machine_mode mode) else if (VALID_INT_MODE_P (mode) || VALID_FP_MODE_P (mode)) return true; + else if (mode == HFmode || mode == HCmode) + return true; /* Lots of MMX code casts 8 byte vector modes to DImode. If we then go on to use that value in smaller contexts, this can easily force a pseudo to be allocated to GENERAL_REGS. Since this is no worse than @@ -21555,10 +21621,27 @@ ix86_scalar_mode_supported_p (scalar_mode mode) return default_decimal_float_supported_p (); else if (mode == TFmode) return true; + else if (mode == HFmode && TARGET_SSE2) + return true; else return default_scalar_mode_supported_p (mode); } +/* Implement TARGET_LIBGCC_FLOATING_POINT_MODE_SUPPORTED_P - return TRUE + if MODE is HFmode, and punt to the generic implementation otherwise. */ + +static bool +ix86_libgcc_floating_mode_supported_p (scalar_float_mode mode) +{ + /* NB: Always return TRUE for HFmode so that the _Float16 type will + be defined by the C front-end for AVX512FP16 intrinsics. We will + issue an error in ix86_expand_move for HFmode if AVX512FP16 isn't + enabled. */ + return ((mode == HFmode && TARGET_SSE2) + ? true + : default_libgcc_floating_mode_supported_p (mode)); +} + /* Implements target hook vector_mode_supported_p. */ static bool ix86_vector_mode_supported_p (machine_mode mode) @@ -23254,13 +23337,15 @@ ix86_get_excess_precision (enum excess_precision_type type) provide would be identical were it not for the unpredictable cases. */ if (!TARGET_80387) - return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT; + return TARGET_SSE2 + ? FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16 + : FLT_EVAL_METHOD_PROMOTE_TO_FLOAT; else if (!TARGET_MIX_SSE_I387) { if (!(TARGET_SSE && TARGET_SSE_MATH)) return FLT_EVAL_METHOD_PROMOTE_TO_LONG_DOUBLE; else if (TARGET_SSE2) - return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT; + return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16; } /* If we are in standards compliant mode, but we know we will @@ -23820,6 +23905,10 @@ ix86_run_selftests (void) #undef TARGET_SCALAR_MODE_SUPPORTED_P #define TARGET_SCALAR_MODE_SUPPORTED_P ix86_scalar_mode_supported_p +#undef TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P +#define TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P \ +ix86_libgcc_floating_mode_supported_p + #undef TARGET_VECTOR_MODE_SUPPORTED_P #define TARGET_VECTOR_MODE_SUPPORTED_P ix86_vector_mode_supported_p diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index 0c2c93daf32..e21922e8782 100644 --- a/gcc/config/i386/i386.h +++ b/gcc/config/i386/i386.h @@ -1018,7 +1018,7 @@ extern const char *host_detect_local_cpu (int argc, const char **argv); #define VALID_SSE2_REG_MODE(MODE) \ ((MODE) == V16QImode || (MODE) == V8HImode || (MODE) == V2DFmode \ || (MODE) == V4QImode || (MODE) == V2HImode || (MODE) == V1SImode \ - || (MODE) == V2DImode || (MODE) == DFmode) + || (MODE) == V2DImode || (MODE) == DFmode || (MODE) == HFmode) #define VALID_SSE_REG_MODE(MODE) \ ((MODE) == V1TImode || (MODE) == TImode \ diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index 8b809c49fe0..dd991c3ffdf 100644 --- a/gcc/config/i386/i386.md +++ b/gcc/config/i386/i386.md @@ -1222,6 +1222,9 @@ (define_mode_iterator MODEF [SF DF]) ;; All x87 floating point modes (define_mode_iterator X87MODEF [SF DF XF]) +;; All x87 floating point modes plus HF +(define_mode_iterator X87MODEFH [SF DF XF HF]) + ;; All SSE floating point modes (define_mode_iterator SSEMODEF [SF DF TF]) (define_mode_attr ssevecmodef [(SF "V4SF") (DF "V2DF") (TF "TF")]) @@ -3130,6 +3133,32 @@ (define_split operands[0] = replace_equiv_address (operands[0], stack_pointer_rtx); }) +(define_insn "*pushhf_rex64" + [(set (match_operand:HF 0 "push_operand" "=X,X") + (match_operand:HF 1 "nonmemory_no_elim_operand" "r,x"))] + "TARGET_64BIT" +{ + /* Anything else should be already split before reg-stack. */ + gcc_assert (which_alternative == 0); + return "push{q}\t%q1"; +} + [(set_attr "type" "push,multi") + (set_attr "mode" "DI,TI") + (set_attr "isa" "*,sse4")]) + +(define_insn "*pushhf" + [(set (match_operand:HF 0 "push_operand" "=X,X") + (match_operand:HF 1 "general_no_elim_operand" "rmF,x"))] + "!TARGET_64BIT" +{ + /* Anything else should be already split before reg-stack. */ + gcc_assert (which_alternative == 0); + return "push{l}\t%k1"; +} + [(set_attr "type" "push,multi") + (set_attr "mode" "SI,TI") + (set_attr "isa" "*,sse4")]) + (define_insn "*pushsf_rex64" [(set (match_operand:SF 0 "push_operand" "=X,X,X") (match_operand:SF 1 "nonmemory_no_elim_operand" "f,rF,v"))] @@ -3158,10 +3187,11 @@ (define_insn "*pushsf" (set_attr "unit" "i387,*,*") (set_attr "mode" "SF,SI,SF")]) +(define_mode_iterator MODESH [SF HF]) ;; %%% Kill this when call knows how to work this out. (define_split - [(set (match_operand:SF 0 "push_operand") - (match_operand:SF 1 "any_fp_register_operand"))] + [(set (match_operand:MODESH 0 "push_operand") + (match_operand:MODESH 1 "any_fp_register_operand"))] "reload_completed" [(set (reg:P SP_REG) (plus:P (reg:P SP_REG) (match_dup 2))) (set (match_dup 0) (match_dup 1))] @@ -3209,8 +3239,8 @@ (define_expand "movtf" "ix86_expand_move (TFmode, operands); DONE;") (define_expand "mov<mode>" - [(set (match_operand:X87MODEF 0 "nonimmediate_operand") - (match_operand:X87MODEF 1 "general_operand"))] + [(set (match_operand:X87MODEFH 0 "nonimmediate_operand") + (match_operand:X87MODEFH 1 "general_operand"))] "" "ix86_expand_move (<MODE>mode, operands); DONE;") @@ -3646,6 +3676,86 @@ (define_insn "*movsf_internal" ] (const_string "*")))]) +(define_insn "*movhf_internal" + [(set (match_operand:HF 0 "nonimmediate_operand" + "=?r,?m,v,v,?r,m,?v,v") + (match_operand:HF 1 "general_operand" + "rmF,rF,C,v, v,v, r,m"))] + "!(MEM_P (operands[0]) && MEM_P (operands[1])) + && (lra_in_progress + || reload_completed + || !CONST_DOUBLE_P (operands[1]) + || (TARGET_SSE && TARGET_SSE_MATH + && standard_sse_constant_p (operands[1], HFmode) == 1) + || memory_operand (operands[0], HFmode))" +{ + switch (get_attr_type (insn)) + { + case TYPE_IMOV: + return "mov{w}\t{%1, %0|%0, %1}"; + + case TYPE_SSELOG1: + return standard_sse_constant_opcode (insn, operands); + + case TYPE_SSEMOV: + return ix86_output_ssemov (insn, operands); + + case TYPE_SSELOG: + if (SSE_REG_P (operands[0])) + return MEM_P (operands[1]) + ? "pinsrw\t{$0, %1, %0|%0, %1, 0}" + : "pinsrw\t{$0, %k1, %0|%0, %k1, 0}"; + else + return MEM_P (operands[1]) + ? "pextrw\t{$0, %1, %0|%0, %1, 0}" + : "pextrw\t{$0, %1, %k0|%k0, %k1, 0}"; + + default: + gcc_unreachable (); + } +} + [(set (attr "isa") + (cond [(eq_attr "alternative" "2,3,4,6,7") + (const_string "sse2") + (eq_attr "alternative" "5") + (const_string "sse4") + ] + (const_string "*"))) + (set (attr "type") + (cond [(eq_attr "alternative" "0,1") + (const_string "imov") + (eq_attr "alternative" "2") + (const_string "sselog1") + (eq_attr "alternative" "4,5,6,7") + (const_string "sselog") + ] + (const_string "ssemov"))) + (set (attr "memory") + (cond [(eq_attr "alternative" "4,6") + (const_string "none") + (eq_attr "alternative" "5") + (const_string "store") + (eq_attr "alternative" "7") + (const_string "load") + ] + (const_string "*"))) + (set (attr "prefix") + (cond [(eq_attr "alternative" "0,1") + (const_string "orig") + ] + (const_string "maybe_vex"))) + (set (attr "mode") + (cond [(eq_attr "alternative" "0,1") + (const_string "HI") + (eq_attr "alternative" "2") + (const_string "V4SF") + (eq_attr "alternative" "4,5,6,7") + (const_string "TI") + (eq_attr "alternative" "3") + (const_string "SF") + ] + (const_string "*")))]) + (define_split [(set (match_operand 0 "any_fp_register_operand") (match_operand 1 "memory_operand"))] diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index b83cd4919bb..2cd0b38fe5b 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -1102,6 +1102,7 @@ typedef _Complex float __attribute__((mode(IC))) _Complex_ibm128; @section Half-Precision Floating Point @cindex half-precision floating point @cindex @code{__fp16} data type +@cindex @code{__Float16} data type On ARM and AArch64 targets, GCC supports half-precision (16-bit) floating point via the @code{__fp16} type defined in the ARM C Language Extensions. @@ -1150,6 +1151,21 @@ calls. It is recommended that portable code use the @code{_Float16} type defined by ISO/IEC TS 18661-3:2015. @xref{Floating Types}. +On x86 targets with @code{target("sse2")} and above, GCC supports half-precision +(16-bit) floating point via the @code{_Float16} type which is defined by +18661-3:2015. For C++, x86 provide a builtin type named @code{_Float16} +which contains same data format as C. + +Without @code{target("avx512fp16")} @code{_Float16} type is storage only, and all +operations will be emulated by soft-fp and @code{float} instructions. + +Soft-fp keeps the intermediate result of the operation at 32-bit precision by defaults, +which may lead to inconsistent behavior between soft-fp and avx512fp16 instructions, +using @option{-fexcess-precision=standard} will force round back after every operation. + +With @option{-mavx512fp16}, instead of calling soft-fp, GCC automatically generates +hardware instructions. + @node Decimal Float @section Decimal Floating Types @cindex decimal floating types diff --git a/gcc/lto/lto-lang.c b/gcc/lto/lto-lang.c index c13c7e45ac1..92f499643b5 100644 --- a/gcc/lto/lto-lang.c +++ b/gcc/lto/lto-lang.c @@ -992,6 +992,9 @@ lto_type_for_mode (machine_mode mode, int unsigned_p) return unsigned_p ? unsigned_intTI_type_node : intTI_type_node; #endif + if (float16_type_node && mode == TYPE_MODE (float16_type_node)) + return float16_type_node; + if (mode == TYPE_MODE (float_type_node)) return float_type_node; diff --git a/gcc/testsuite/gcc.target/i386/sse2-float16-1.c b/gcc/testsuite/gcc.target/i386/sse2-float16-1.c new file mode 100644 index 00000000000..1b645eb499d --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/sse2-float16-1.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mno-sse2" } */ + +_Float16/* { dg-error "is not supported on this target" } */ +foo (_Float16 x) /* { dg-error "is not supported on this target" } */ +{ + return x; +} diff --git a/gcc/testsuite/gcc.target/i386/sse2-float16-2.c b/gcc/testsuite/gcc.target/i386/sse2-float16-2.c new file mode 100644 index 00000000000..3da7683fc31 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/sse2-float16-2.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -msse2 -mno-avx512f" } */ + +union flt +{ + _Float16 flt; + short s; +}; + +_Float16 +foo (union flt x) +{ + return x.flt; +} + +/* { dg-final { scan-assembler {(?n)pinsrw[\t ].*%xmm0} } } */ diff --git a/gcc/testsuite/gcc.target/i386/sse2-float16-3.c b/gcc/testsuite/gcc.target/i386/sse2-float16-3.c new file mode 100644 index 00000000000..60ff9d4ab80 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/sse2-float16-3.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -msse2 -mno-avx512f" } */ + +#include<complex.h> + +_Complex _Float16 +foo (_Complex _Float16 x) +{ + return x; +} + +/* { dg-final { scan-assembler {(?n)movd[\t ].*%xmm0} } } */ -- 2.18.1