[Patch 4/5] rs6000, Test 128-bit shifts for just the int128 type.

will schmidt will_schmidt@vnet.ibm.com
Fri Aug 14 17:35:26 GMT 2020


On Tue, 2020-08-11 at 12:23 -0700, Carl Love wrote:
> Segher, Will:
> 
> Patch 4 adds 128-bit integer shift instruction support.


I suggest having a few more words here to better describe what this
patch is doing. 
i.e. 
This is adding the VEC_I128 iterator which contains the V1TI and TI
types, and modifying existing define_insns to add handling for the
VEC_I128 iterator.


> 
>                  Carl Love
> 
> ---------------------------------------------------------
> Test 128-bit shifts for just the int128 type.
> 
> gcc/ChangeLog
> 
> 2020-08-10  Carl Love  <cel@us.ibm.com>
> 	* config/rs6000/altivec.md (altivec_vslq, altivec_vsrq): Add mode
> 	VEC_I128.


Maybe also rename to altivec_vslq_<mode> and altivec_vsrq_<mode>.  


> 	* config/rs6000/vector.md (VEC_I128): New mode iterator.

ok

> 	(vashlv1ti3): Change to vashl<mode>3, mode VEC_I128.
> 	(vlshrv1ti3): Change to vlshr<mode>3, mode VEC_I128.


> 	* config/rs6000/vsx.md (UNSPEC_XXSWAPD_V1TI): Change to
> 	UNSPEC_XXSWAPD_VEC_I128.

s/Change/Rename/


> 	(xxswapd_v1ti): Change to xxswapd_<mode>, mode VEC_I128.
> 
> gcc/testsuite/ChangeLog
> 
> 2020-08-10  Carl Love  <cel@us.ibm.com>
> 	gcc.target/powerpc/int_128bit-runnable.c: Add shift_right, shift_left
> 	tests.
> ---
>  gcc/config/rs6000/altivec.md                  | 16 +++++------
>  gcc/config/rs6000/vector.md                   | 27 ++++++++++---------
>  gcc/config/rs6000/vsx.md                      | 14 +++++-----
>  .../gcc.target/powerpc/int_128bit-runnable.c  | 24 +++++++++++++++--
>  4 files changed, 52 insertions(+), 29 deletions(-)
> 
> diff --git a/gcc/config/rs6000/altivec.md b/gcc/config/rs6000/altivec.md
> index 2763d920828..cba39852070 100644
> --- a/gcc/config/rs6000/altivec.md
> +++ b/gcc/config/rs6000/altivec.md
> @@ -2219,10 +2219,10 @@
>    "vsl<VI_char> %0,%1,%2"
>    [(set_attr "type" "vecsimple")])
> 
> -(define_insn "altivec_vslq"
> -  [(set (match_operand:V1TI 0 "vsx_register_operand" "=v")
> -	(ashift:V1TI (match_operand:V1TI 1 "vsx_register_operand" "v")
> -		     (match_operand:V1TI 2 "vsx_register_operand" "v")))]
> +(define_insn "altivec_vslq_<mode>"
> +  [(set (match_operand:VEC_I128 0 "vsx_register_operand" "=v")
> +	(ashift:VEC_I128 (match_operand:VEC_I128 1 "vsx_register_operand" "v")
> +		     (match_operand:VEC_I128 2 "vsx_register_operand" "v")))]
>    "TARGET_TI_VECTOR_OPS"
>    /* Shift amount in needs to be in bits[57:63] of 128-bit operand. */
>    "vslq %0,%1,%2"

ok

> @@ -2236,10 +2236,10 @@
>    "vsr<VI_char> %0,%1,%2"
>    [(set_attr "type" "vecsimple")])
> 
> -(define_insn "altivec_vsrq"
> -  [(set (match_operand:V1TI 0 "vsx_register_operand" "=v")
> -	(lshiftrt:V1TI (match_operand:V1TI 1 "vsx_register_operand" "v")
> -		       (match_operand:V1TI 2 "vsx_register_operand" "v")))]
> +(define_insn "altivec_vsrq_<mode>"
> +  [(set (match_operand:VEC_I128 0 "vsx_register_operand" "=v")
> +	(lshiftrt:VEC_I128 (match_operand:VEC_I128 1 "vsx_register_operand" "v")
> +			   (match_operand:VEC_I128 2 "vsx_register_operand" "v")))]
>    "TARGET_TI_VECTOR_OPS"
>    /* Shift amount in needs to be in bits[57:63] of 128-bit operand. */
>    "vsrq %0,%1,%2"

ok

> diff --git a/gcc/config/rs6000/vector.md b/gcc/config/rs6000/vector.md
> index 2deff282076..682aabc4657 100644
> --- a/gcc/config/rs6000/vector.md
> +++ b/gcc/config/rs6000/vector.md
> @@ -26,6 +26,9 @@
>  ;; Vector int modes
>  (define_mode_iterator VEC_I [V16QI V8HI V4SI V2DI])
> 
> +;; 128-bit int modes
> +(define_mode_iterator VEC_I128 [V1TI TI])
> +
>  ;; Vector int modes for parity
>  (define_mode_iterator VEC_IP [V8HI
>  			      V4SI
> @@ -1635,17 +1638,17 @@
>    "")
> 
>  ;; No immediate version of this 128-bit instruction
> -(define_expand "vashlv1ti3"
> -  [(set (match_operand:V1TI 0 "vsx_register_operand" "=v")
> -	(ashift:V1TI (match_operand:V1TI 1 "vsx_register_operand" "v")
> -		     (match_operand:V1TI 2 "vsx_register_operand" "v")))]
> +(define_expand "vashl<mode>3"
> +  [(set (match_operand:VEC_I128 0 "vsx_register_operand" "=v")
> +	(ashift:VEC_I128 (match_operand:VEC_I128 1 "vsx_register_operand")
> +			 (match_operand:VEC_I128 2 "vsx_register_operand")))]
>    "TARGET_TI_VECTOR_OPS"
>  {
>    /* Shift amount in needs to be put in bits[57:63] of 128-bit operand2. */
> -  rtx tmp = gen_reg_rtx (V1TImode);
> +  rtx tmp = gen_reg_rtx (<MODE>mode);
> 
>    emit_insn(gen_xxswapd_v1ti (tmp, operands[2]));
> -  emit_insn(gen_altivec_vslq (operands[0], operands[1], tmp));
> +  emit_insn(gen_altivec_vslq_<mode> (operands[0], operands[1], tmp));
>    DONE;
>  })
> 
> @@ -1658,17 +1661,17 @@
>    "")
> 
>  ;; No immediate version of this 128-bit instruction
> -(define_expand "vlshrv1ti3"
> -  [(set (match_operand:V1TI 0 "vsx_register_operand" "=v")
> -	(lshiftrt:V1TI (match_operand:V1TI 1 "vsx_register_operand" "v")
> -		       (match_operand:V1TI 2 "vsx_register_operand" "v")))]
> +(define_expand "vlshr<mode>3"
> +  [(set (match_operand:VEC_I128 0 "vsx_register_operand" "=v")
> +	(lshiftrt:VEC_I128 (match_operand:VEC_I128 1 "vsx_register_operand")
> +			   (match_operand:VEC_I128 2 "vsx_register_operand")))]
>    "TARGET_TI_VECTOR_OPS"
>  {
>    /* Shift amount in needs to be put into bits[57:63] of 128-bit operand2. */
> -  rtx tmp = gen_reg_rtx (V1TImode);
> +  rtx tmp = gen_reg_rtx (<MODE>mode);
> 
>    emit_insn(gen_xxswapd_v1ti (tmp, operands[2]));
> -  emit_insn(gen_altivec_vsrq (operands[0], operands[1], tmp));
> +  emit_insn(gen_altivec_vsrq_<mode> (operands[0], operands[1], tmp));
>    DONE;
>  })
> 
> diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
> index 998af3908ad..5be535808b3 100644
> --- a/gcc/config/rs6000/vsx.md
> +++ b/gcc/config/rs6000/vsx.md
> @@ -367,7 +367,7 @@
>     UNSPEC_INSERTR
>     UNSPEC_REPLACE_ELT
>     UNSPEC_REPLACE_UN
> -	UNSPEC_XXSWAPD_V1TI
> +	UNSPEC_XXSWAPD_VEC_I128
>    ])


double-check whitespace indentation.


> 
>  (define_int_iterator XVCVBF16	[UNSPEC_VSX_XVCVSPBF16
> @@ -3144,12 +3144,12 @@
>    "xxpermdi %x0,%x1,%x1,2"
>    [(set_attr "type" "vecperm")])
> 
> -;; Swap upper/lower 64-bit values in a 128-bit vector
> -(define_insn "xxswapd_v1ti"
> -  [(set (match_operand:V1TI 0 "vsx_register_operand" "=v")
> -	(unspec:V1TI [(match_operand:V1TI 1 "vsx_register_operand" "v")
> -		      (parallel [(const_int 0)(const_int 1)])]
> -                     UNSPEC_XXSWAPD_V1TI))]
> +;; Swap upper/lower 64-bit values in V1TI or TI type
> +(define_insn "xxswapd_<mode>"
> +  [(set (match_operand:VEC_I128 0 "vsx_register_operand" "=v")
> +	(unspec:VEC_I128 [(match_operand:VEC_I128 1 "vsx_register_operand" "v")
> +			  (parallel [(const_int 0)(const_int 1)])]
> +                     UNSPEC_XXSWAPD_VEC_I128))]
>    "TARGET_POWER10"
>  ;; AIX does not support extended mnemonic xxswapd.  Use the basic
>  ;; mnemonic xxpermdi instead.
> diff --git a/gcc/testsuite/gcc.target/powerpc/int_128bit-runnable.c b/gcc/testsuite/gcc.target/powerpc/int_128bit-runnable.c
> index d1e69cea021..b074d83bd68 100644
> --- a/gcc/testsuite/gcc.target/powerpc/int_128bit-runnable.c
> +++ b/gcc/testsuite/gcc.target/powerpc/int_128bit-runnable.c
> @@ -53,6 +53,18 @@ void print_i128(__int128_t val)
> 
>  void abort (void);
> 
> +__attribute__((noinline))
> +__int128_t shift_right (__int128_t a, __uint128_t b)
> +{
> +  return a >> b;
> +}
> +
> +__attribute__((noinline))
> +__int128_t shift_left (__int128_t a, __uint128_t b)
> +{
> +  return a << b;
> +}
> +
>  int main ()
>  {
>    int i, result_int;
> @@ -141,10 +153,12 @@ int main ()
>  #endif
>    }
> 
> -  arg1 = 3;
> +  //  arg1 = 3;
> +  arg1 = vec_result[0];
>    uarg2 = 4;
>    expected_result = arg1*16;

Just drop the lines that are commented out with "//" 
Here and below.

> 
> +  //  result = shift_left(arg1, uarg2);
>    result = arg1 << uarg2;
> 
>    if (result != expected_result) {
> @@ -225,10 +239,16 @@ int main ()
>  #endif
>    }
> 
> -  arg1 = 48;
> +  //  arg1 = 48;
> +
> +  // use the previous result to try and keep gcc from doing the shift
> +  // at compile time
> +  arg1 = vec_uresult[0];
>    uarg2 = 4;
>    expected_result = arg1/16;
> 
> +  //Not getting 128-bit shift inst generated
> +  //  result = shift_right (arg1, uarg2);
>    result = arg1 >> uarg2;
> 
>    if (result != expected_result) {



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