https://gcc.gnu.org/g:d45a856584f830d70936911ddc85dc23ee873217
commit d45a856584f830d70936911ddc85dc23ee873217 Author: Michael Meissner <[email protected]> Date: Thu Oct 23 19:30:45 2025 -0400 Add conversions between _Float16 and float/double. 2025-10-23 Michael Meissner <[email protected]> gcc/ * config/rs6000/float16.md (FP16_HW): New mode iterator. (extendhf<mode>2): Add support converting between HFmode and SFmode/DFmoded if we are on power9 or later. (trunc<mode>hf2): Likewise. * config/rs6000/rs6000.h (TARGET_FLOAT16_HW): New macro. (FP16_HW_SCALAR_MODE_P): Likewise. Diff: --- gcc/config/rs6000/float16.md | 22 ++++++++++++++++++++++ gcc/config/rs6000/rs6000.h | 8 ++++++++ 2 files changed, 30 insertions(+) diff --git a/gcc/config/rs6000/float16.md b/gcc/config/rs6000/float16.md index d186d8e7d601..31e2e43134c9 100644 --- a/gcc/config/rs6000/float16.md +++ b/gcc/config/rs6000/float16.md @@ -25,6 +25,10 @@ (define_mode_iterator FP16 [(BF "TARGET_BFLOAT16") (HF "TARGET_FLOAT16")]) +;; Mode iterator for 16-bit floating point modes on machines with +;; hardware support both as a scalar and as a vector. +(define_mode_iterator FP16_HW [(HF "TARGET_FLOAT16_HW")]) + ;; Mode attribute giving the vector mode for a 16-bit floating point ;; scalar in both upper and lower case. (define_mode_attr FP16_VECTOR8 [(BF "V8BF") @@ -122,3 +126,21 @@ } [(set_attr "type" "veclogical,vecperm") (set_attr "prefixed" "*,yes")]) + +;; Convert IEEE 16-bit floating point to/from other floating point modes. + +(define_insn "extendhf<mode>2" + [(set (match_operand:SFDF 0 "vsx_register_operand" "=wa") + (float_extend:SFDF + (match_operand:HF 1 "vsx_register_operand" "wa")))] + "TARGET_FLOAT16_HW" + "xscvhpdp %x0,%x1" + [(set_attr "type" "fpsimple")]) + +(define_insn "trunc<mode>hf2" + [(set (match_operand:HF 0 "vsx_register_operand" "=wa") + (float_truncate:HF + (match_operand:SFDF 1 "vsx_register_operand" "wa")))] + "TARGET_FLOAT16_HW" + "xscvdphp %x0,%x1" + [(set_attr "type" "fpsimple")]) diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h index 0249219bbbc9..eb60573ae4bd 100644 --- a/gcc/config/rs6000/rs6000.h +++ b/gcc/config/rs6000/rs6000.h @@ -343,11 +343,19 @@ extern const char *host_detect_local_cpu (int argc, const char **argv); || ((MODE) == TDmode) \ || (!TARGET_FLOAT128_TYPE && FLOAT128_IEEE_P (MODE))) +/* Do we have conversion support in hardware for the 16-bit floating point? */ +#define TARGET_FLOAT16_HW (TARGET_FLOAT16 && TARGET_POWER9) + /* Is this a valid 16-bit scalar floating point mode? */ #define FP16_SCALAR_MODE_P(MODE) \ (((MODE) == HFmode && TARGET_FLOAT16) \ || ((MODE) == BFmode && TARGET_BFLOAT16)) +/* Is this a valid 16-bit scalar floating point mode that has hardware + conversions? */ +#define FP16_HW_SCALAR_MODE_P(MODE) \ + ((MODE) == HFmode && TARGET_FLOAT16_HW) + /* Is this a valid 16-bit vector floating point mode? */ #define FP16_VECTOR_MODE_P(MODE) \ (((MODE) == V8HFmode && TARGET_FLOAT16) \
