Hi all,
On 17/01/2020 16:46, Dennis Zhang wrote:
Hi all,
This patch is part of a series adding support for Armv8.6-A features.
It depends on Arm BFMode patch
https://gcc.gnu.org/ml/gcc-patches/2019-12/msg01448.html
This patch implements intrinsics to convert between bfloat16 and float32
formats.
ACLE documents are at https://developer.arm.com/docs/101028/latest
ISA documents are at https://developer.arm.com/docs/ddi0596/latest
Regression tested.
Is it OK for trunk please?
Thanks,
Dennis
gcc/ChangeLog:
2020-01-17 Dennis Zhang <dennis.zh...@arm.com>
* config/arm/arm_bf16.h (vcvtah_f32_bf16, vcvth_bf16_f32): New.
* config/arm/arm_neon.h (vcvt_f32_bf16, vcvtq_low_f32_bf16): New.
(vcvtq_high_f32_bf16, vcvt_bf16_f32): New.
(vcvtq_low_bf16_f32, vcvtq_high_bf16_f32): New.
* config/arm/arm_neon_builtins.def (vbfcvt, vbfcvt_high): New entries.
(vbfcvtv4sf, vbfcvtv4sf_high): Likewise.
* config/arm/iterators.md (VBFCVT, VBFCVTM): New mode iterators.
(V_bf_low, V_bf_cvt_m): New mode attributes.
* config/arm/neon.md (neon_vbfcvtv4sf<VBFCVT:mode>): New.
(neon_vbfcvtv4sf_highv8bf, neon_vbfcvtsf): New.
(neon_vbfcvt<VBFCVT:mode>, neon_vbfcvt_highv8bf): New.
(neon_vbfcvtbf_cvtmode<mode>, neon_vbfcvtbf): New
* config/arm/unspecs.md (UNSPEC_BFCVT, UNSPEC_BFCVT_HIG): New.
gcc/testsuite/ChangeLog:
2020-01-17 Dennis Zhang <dennis.zh...@arm.com>
* gcc.target/arm/simd/bf16_cvt_1.c: New test.
The tests are updated in this patch for assembly test.
Rebased to trunk top.
Is it OK to commit please?
Cheers
Dennis
diff --git a/gcc/config/arm/arm_bf16.h b/gcc/config/arm/arm_bf16.h
index decf23f3834..1aa593192c0 100644
--- a/gcc/config/arm/arm_bf16.h
+++ b/gcc/config/arm/arm_bf16.h
@@ -34,6 +34,20 @@ extern "C" {
typedef __bf16 bfloat16_t;
typedef float float32_t;
+__extension__ extern __inline float32_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvtah_f32_bf16 (bfloat16_t __a)
+{
+ return __builtin_neon_vbfcvtbf (__a);
+}
+
+__extension__ extern __inline bfloat16_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvth_bf16_f32 (float32_t __a)
+{
+ return __builtin_neon_vbfcvtsf (__a);
+}
+
#ifdef __cplusplus
}
#endif
diff --git a/gcc/config/arm/arm_neon.h b/gcc/config/arm/arm_neon.h
index 81c407f5152..a66961d0c51 100644
--- a/gcc/config/arm/arm_neon.h
+++ b/gcc/config/arm/arm_neon.h
@@ -19379,6 +19379,55 @@ vbfdotq_lane_f32 (float32x4_t __r, bfloat16x8_t __a, bfloat16x4_t __b,
#pragma GCC pop_options
+#pragma GCC push_options
+#pragma GCC target ("arch=armv8.2-a+bf16")
+
+__extension__ extern __inline float32x4_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvt_f32_bf16 (bfloat16x4_t __a)
+{
+ return __builtin_neon_vbfcvtv4bf (__a);
+}
+
+__extension__ extern __inline float32x4_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvtq_low_f32_bf16 (bfloat16x8_t __a)
+{
+ return __builtin_neon_vbfcvtv8bf (__a);
+}
+
+__extension__ extern __inline float32x4_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvtq_high_f32_bf16 (bfloat16x8_t __a)
+{
+ return __builtin_neon_vbfcvt_highv8bf (__a);
+}
+
+__extension__ extern __inline bfloat16x4_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvt_bf16_f32 (float32x4_t __a)
+{
+ return __builtin_neon_vbfcvtv4sfv4bf (__a);
+}
+
+__extension__ extern __inline bfloat16x8_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvtq_low_bf16_f32 (float32x4_t __a)
+{
+ return __builtin_neon_vbfcvtv4sfv8bf (__a);
+}
+
+/* The 'inactive' operand is not converted but it provides the
+ low 64 bits to assemble the final 128-bit result. */
+__extension__ extern __inline bfloat16x8_t
+__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
+vcvtq_high_bf16_f32 (bfloat16x8_t inactive, float32x4_t __a)
+{
+ return __builtin_neon_vbfcvtv4sf_highv8bf (inactive, __a);
+}
+
+#pragma GCC pop_options
+
#ifdef __cplusplus
}
#endif
diff --git a/gcc/config/arm/arm_neon_builtins.def b/gcc/config/arm/arm_neon_builtins.def
index 4b4d1c808d8..48c06c43a17 100644
--- a/gcc/config/arm/arm_neon_builtins.def
+++ b/gcc/config/arm/arm_neon_builtins.def
@@ -385,3 +385,9 @@ VAR1 (USTERNOP, usmmla, v16qi)
VAR2 (TERNOP, vbfdot, v2sf, v4sf)
VAR2 (MAC_LANE_PAIR, vbfdot_lanev4bf, v2sf, v4sf)
VAR2 (MAC_LANE_PAIR, vbfdot_lanev8bf, v2sf, v4sf)
+
+VAR2 (UNOP, vbfcvt, sf, bf)
+VAR2 (UNOP, vbfcvt, v4bf, v8bf)
+VAR1 (UNOP, vbfcvt_high, v8bf)
+VAR2 (UNOP, vbfcvtv4sf, v4bf, v8bf)
+VAR1 (BINOP, vbfcvtv4sf_high, v8bf)
diff --git a/gcc/config/arm/iterators.md b/gcc/config/arm/iterators.md
index ab30c371583..5f4e3d12358 100644
--- a/gcc/config/arm/iterators.md
+++ b/gcc/config/arm/iterators.md
@@ -229,6 +229,10 @@
;; Modes for polynomial or float values.
(define_mode_iterator VPF [V8QI V16QI V2SF V4SF])
+;; Modes for BF16 convert instructions.
+(define_mode_iterator VBFCVT [V4BF V8BF])
+(define_mode_iterator VBFCVTM [V2SI SF])
+
;;----------------------------------------------------------------------------
;; Code iterators
;;----------------------------------------------------------------------------
@@ -747,6 +751,12 @@
(V2SF "") (V4SF "")
(DI "_neon") (V2DI "")])
+;; To select the low 64 bits of a vector.
+(define_mode_attr V_bf_low [(V4BF "P") (V8BF "e")])
+
+;; To generate intermediate modes for BF16 scalar convert.
+(define_mode_attr V_bf_cvt_m [(V2SI "BF") (SF "V2SI")])
+
;; Scalars to be presented to scalar multiplication instructions
;; must satisfy the following constraints.
diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md
index fae82131e24..f5286d9c4b1 100644
--- a/gcc/config/arm/neon.md
+++ b/gcc/config/arm/neon.md
@@ -6660,3 +6660,80 @@ if (BYTES_BIG_ENDIAN)
}
[(set_attr "type" "neon_dot<q>")]
)
+
+(define_insn "neon_vbfcvtv4sf<VBFCVT:mode>"
+ [(set (match_operand:VBFCVT 0 "register_operand" "=w")
+ (unspec:VBFCVT [(match_operand:V4SF 1 "register_operand" "w")]
+ UNSPEC_BFCVT))]
+ "TARGET_BF16_SIMD"
+ "vcvt.bf16.f32\\t%<V_bf_low>0, %q1"
+ [(set_attr "type" "neon_fp_cvt_narrow_s_q")]
+)
+
+(define_insn "neon_vbfcvtv4sf_highv8bf"
+ [(set (match_operand:V8BF 0 "register_operand" "=w")
+ (unspec:V8BF [(match_operand:V8BF 1 "register_operand" "0")
+ (match_operand:V4SF 2 "register_operand" "w")]
+ UNSPEC_BFCVT_HIGH))]
+ "TARGET_BF16_SIMD"
+ "vcvt.bf16.f32\\t%f0, %q2"
+ [(set_attr "type" "neon_fp_cvt_narrow_s_q")]
+)
+
+(define_insn "neon_vbfcvtsf"
+ [(set (match_operand:BF 0 "register_operand" "=t")
+ (unspec:BF [(match_operand:SF 1 "register_operand" "t")]
+ UNSPEC_BFCVT))]
+ "TARGET_BF16_FP"
+ "vcvtb.bf16.f32\\t%0, %1"
+ [(set_attr "type" "f_cvt")]
+)
+
+(define_insn "neon_vbfcvt<VBFCVT:mode>"
+ [(set (match_operand:V4SF 0 "register_operand" "=w")
+ (unspec:V4SF [(match_operand:VBFCVT 1 "register_operand" "w")]
+ UNSPEC_BFCVT))]
+ "TARGET_BF16_SIMD"
+ "vshll.u32\\t%q0, %<V_bf_low>1, #16"
+ [(set_attr "type" "neon_shift_imm_q")]
+)
+
+(define_insn "neon_vbfcvt_highv8bf"
+ [(set (match_operand:V4SF 0 "register_operand" "=w")
+ (unspec:V4SF [(match_operand:V8BF 1 "register_operand" "w")]
+ UNSPEC_BFCVT_HIGH))]
+ "TARGET_BF16_SIMD"
+ "vshll.u32\\t%q0, %f1, #16"
+ [(set_attr "type" "neon_shift_imm_q")]
+)
+
+;; Convert a BF scalar operand to SF via VSHL.
+;; VSHL doesn't accept 32-bit registers where the BF and SF scalar operands
+;; would be allocated, therefore the operands must be converted to intermediate
+;; vectors (i.e. V2SI) in order to apply 64-bit registers.
+(define_expand "neon_vbfcvtbf"
+ [(match_operand:SF 0 "register_operand")
+ (unspec:SF [(match_operand:BF 1 "register_operand")] UNSPEC_BFCVT)]
+ "TARGET_BF16_FP"
+{
+ rtx op0 = gen_reg_rtx (V2SImode);
+ rtx op1 = gen_reg_rtx (V2SImode);
+ emit_insn (gen_neon_vbfcvtbf_cvtmodev2si (op1, operands[1]));
+ emit_insn (gen_neon_vshl_nv2si (op0, op1, gen_int_mode(16, SImode)));
+ emit_insn (gen_neon_vbfcvtbf_cvtmodesf (operands[0], op0));
+ DONE;
+})
+
+;; Convert BF mode to V2SI and V2SI to SF.
+;; Implement this by allocating a 32-bit operand in the low half of a 64-bit
+;; register indexed by a 32-bit sub-register number.
+;; This will generate reloads but compiler can optimize out the moves.
+;; Use 'x' constraint to guarantee the 32-bit sub-registers in an indexable
+;; range so that to avoid extra moves.
+(define_insn "neon_vbfcvtbf_cvtmode<mode>"
+ [(set (match_operand:VBFCVTM 0 "register_operand" "=x")
+ (unspec:VBFCVTM [(match_operand:<V_bf_cvt_m> 1 "register_operand" "0")]
+ UNSPEC_BFCVT))]
+ "TARGET_BF16_FP"
+ ""
+)
diff --git a/gcc/config/arm/unspecs.md b/gcc/config/arm/unspecs.md
index c8f3f95c7f3..b36ae512a6e 100644
--- a/gcc/config/arm/unspecs.md
+++ b/gcc/config/arm/unspecs.md
@@ -506,4 +506,6 @@
UNSPEC_MATMUL_S
UNSPEC_MATMUL_U
UNSPEC_MATMUL_US
+ UNSPEC_BFCVT
+ UNSPEC_BFCVT_HIGH
])
diff --git a/gcc/testsuite/gcc.target/arm/simd/bf16_cvt_1.c b/gcc/testsuite/gcc.target/arm/simd/bf16_cvt_1.c
new file mode 100644
index 00000000000..04d4eee8e47
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/simd/bf16_cvt_1.c
@@ -0,0 +1,51 @@
+/* { dg-do assemble } */
+/* { dg-require-effective-target arm_v8_2a_bf16_neon_ok } */
+/* { dg-options "-save-temps -O2" } */
+/* { dg-add-options arm_v8_2a_bf16_neon } */
+
+#include "arm_neon.h"
+
+float32_t test_vcvtah_f32_bf16 (bfloat16_t a)
+{
+ return vcvtah_f32_bf16 (a);
+}
+
+bfloat16_t test_vcvth_bf16_f32 (float32_t a)
+{
+ return vcvth_bf16_f32 (a);
+}
+
+float32x4_t test_vcvt_f32_bf16 (bfloat16x4_t a)
+{
+ return vcvt_f32_bf16 (a);
+}
+
+float32x4_t test_vcvtq_low_f32_bf16 (bfloat16x8_t a)
+{
+ return vcvtq_low_f32_bf16 (a);
+}
+
+float32x4_t test_vcvtq_high_f32_bf16 (bfloat16x8_t a)
+{
+ return vcvtq_high_f32_bf16 (a);
+}
+
+bfloat16x4_t test_vcvt_bf16_f32 (float32x4_t a)
+{
+ return vcvt_bf16_f32 (a);
+}
+
+bfloat16x8_t test_vcvtq_low_bf16_f32 (float32x4_t a)
+{
+ return vcvtq_low_bf16_f32 (a);
+}
+
+bfloat16x8_t test_vcvtq_high_bf16_f32 (bfloat16x8_t inactive, float32x4_t a)
+{
+ return vcvtq_high_bf16_f32 (inactive, a);
+}
+
+/* { dg-final { scan-assembler-times {vcvtb.bf16.f32\ts[0-9]+, s[0-9]+\n} 1 } } */
+/* { dg-final { scan-assembler-times {vcvt.bf16.f32\td[0-9]+, q[0-9]+\n} 3 } } */
+/* { dg-final { scan-assembler-times {vshl.i32\td[0-9]+, d[0-9]+, #16} 1 } } */
+/* { dg-final { scan-assembler-times {vshll.u32\tq[0-9]+, d[0-9]+, #16} 3 } } */
