[i386] : Fix TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL handling.

Message ID CAFULd4ZsrLV6v4t_Qz+zr8Y=het=YD1AqR+YoYfA=HPumaDTSA@mail.gmail.com
State New
Headers show
Series
  • [i386] : Fix TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL handling.
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Commit Message

Uros Bizjak Jan. 31, 2020, 2:12 p.m.
The reason for TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL on AMD target is
only insn size, as advised in e.g. Software Optimization Guide for the
AMD Family 15h Processors [1], section 7.1.2, where it is said:

--quote--
7.1.2 Reduce Instruction SizeOptimization

Reduce the size of instructions when possible.

Rationale

Using smaller instruction sizes improves instruction fetch throughput.
Specific examples include the following:

*In SIMD code, use the single-precision (PS) form of instructions
instead of the double-precision (PD) form. For example, for register
to register moves, MOVAPS achieves the same result as MOVAPD, but uses
one less byte to encode the instruction and has no prefix byte. Other
examples in which single-precision forms can be substituted for
double-precision forms include MOVUPS, MOVNTPS, XORPS, ORPS, ANDPS,
and SHUFPS.
...
--/quote--

Please note that this optimization applies only to non-AVX forms, as
demonstrated by:

   0:   0f 28 c8                movaps %xmm0,%xmm1
   3:   66 0f 28 c8             movapd %xmm0,%xmm1
   7:   c5 f8 28 d1             vmovaps %xmm1,%xmm2
   b:   c5 f9 28 d1             vmovapd %xmm1,%xmm2

Also note that MOVDQA is missing in the above optimization. It is
harmful to substitute MOVDQA with MOVAPS, as it can (and does)
introduce +1 cycle forwarding penalty between FLT (FPA/FPM) and INT
(VALU) FP clusters.

[1] https://www.amd.com/system/files/TechDocs/47414_15h_sw_opt_guide.pdf

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Will be committed to mainline soon.

Uros.

2020-01-31  UroŇ° Bizjak  <ubizjak@gmail.com>

    * config/i386/i386.md (*movoi_internal_avx): Do not check for
    TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL.  Remove MODE_V8SF handling.
    (*movti_internal): Do not check for
    TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL.
    (*movtf_internal): Move check for TARGET_SSE2 and size optimization
    just after check for TARGET_AVX.
    (*movdf_internal): Ditto.
    * config/i386/mmx.md (*mov<mode>_internal): Do not check for
    TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL.
    * config/i386/sse.md (mov<mode>_internal): Only check
     TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL with V2DFmode.  Move check
    for TARGET_SSE2 and size optimization just after check for TARGET_AVX.
    (<sse>_andnot<mode>3<mask_name>): Move check for
    TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL after check for TARGET_AVX.
    (<code><mode>3<mask_name>): Ditto.
    (*andnot<mode>3): Ditto.
    (*andnottf3): Ditto.
    (*<code><mode>3): Ditto.
    (*<code>tf3): Ditto.
    (*andnot<VI:mode>3): Remove
    TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL handling.
    (<mask_codefor><code><VI48_AVX_AVX512F:mode>3<mask_name>): Ditto.
    (*<code><VI12_AVX_AVX512F:mode>3): Ditto.
    (sse4_1_blendv<ssemodesuffix>): Ditto.
    * config/i386/x86-tune.def (X86_TUNE_SSE_UNALIGNED_STORE_OPTIMAL):
    Explain that tune applies to 128bit instructions only.

Patch

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 9f0077d59a97..e2675da24c17 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -1949,18 +1949,14 @@ 
       if (misaligned_operand (operands[0], OImode)
 	  || misaligned_operand (operands[1], OImode))
 	{
-	  if (get_attr_mode (insn) == MODE_V8SF)
-	    return "vmovups\t{%1, %0|%0, %1}";
-	  else if (get_attr_mode (insn) == MODE_XI)
+	  if (get_attr_mode (insn) == MODE_XI)
 	    return "vmovdqu32\t{%1, %0|%0, %1}";
 	  else
 	    return "vmovdqu\t{%1, %0|%0, %1}";
 	}
       else
 	{
-	  if (get_attr_mode (insn) == MODE_V8SF)
-	    return "vmovaps\t{%1, %0|%0, %1}";
-	  else if (get_attr_mode (insn) == MODE_XI)
+	  if (get_attr_mode (insn) == MODE_XI)
 	    return "vmovdqa32\t{%1, %0|%0, %1}";
 	  else
 	    return "vmovdqa\t{%1, %0|%0, %1}";
@@ -1980,8 +1976,6 @@ 
 	       (and (eq_attr "alternative" "1")
 		    (match_test "TARGET_AVX512VL"))
 		 (const_string "XI")
-	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
-		 (const_string "V8SF")
 	      ]
 	      (const_string "OI")))])
 
@@ -2060,11 +2054,10 @@ 
 	       (match_test "TARGET_AVX")
 		 (const_string "TI")
 	       (ior (not (match_test "TARGET_SSE2"))
-		    (ior (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
-			 (and (eq_attr "alternative" "5")
-			      (match_test "TARGET_SSE_TYPELESS_STORES"))))
+		    (match_test "optimize_function_for_size_p (cfun)"))
 		 (const_string "V4SF")
-	       (match_test "optimize_function_for_size_p (cfun)")
+	       (and (eq_attr "alternative" "5")
+		    (match_test "TARGET_SSE_TYPELESS_STORES"))
 		 (const_string "V4SF")
 	       ]
 	       (const_string "TI")))
@@ -2243,12 +2236,10 @@ 
 	      (cond [(ior (match_operand 0 "ext_sse_reg_operand")
 			  (match_operand 1 "ext_sse_reg_operand"))
 		       (const_string "TI")
-		     (ior (not (match_test "TARGET_SSE2"))
-			  (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		       (const_string "V4SF")
 		     (match_test "TARGET_AVX")
 		       (const_string "TI")
-		     (match_test "optimize_function_for_size_p (cfun)")
+		     (ior (not (match_test "TARGET_SSE2"))
+		 	  (match_test "optimize_function_for_size_p (cfun)"))
 		       (const_string "V4SF")
 		    ]
 		    (const_string "TI"))
@@ -2453,12 +2444,10 @@ 
 	      (cond [(ior (match_operand 0 "ext_sse_reg_operand")
 			  (match_operand 1 "ext_sse_reg_operand"))
 		       (const_string "XI")
-		     (ior (not (match_test "TARGET_SSE2"))
-			  (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		       (const_string "V4SF")
 		     (match_test "TARGET_AVX")
 		       (const_string "TI")
-		     (match_test "optimize_function_for_size_p (cfun)")
+		     (ior (not (match_test "TARGET_SSE2"))
+			  (match_test "optimize_function_for_size_p (cfun)"))
 		       (const_string "V4SF")
 		    ]
 		    (const_string "TI"))
@@ -3324,14 +3313,14 @@ 
 		 (const_string "DI")
 	       (match_test "TARGET_AVX")
 		 (const_string "TI")
+	       (ior (not (match_test "TARGET_SSE2"))
+		    (match_test "optimize_function_for_size_p (cfun)"))
+		 (const_string "V4SF")
 	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
 		 (const_string "V4SF")
 	       (and (eq_attr "alternative" "2")
 		    (match_test "TARGET_SSE_TYPELESS_STORES"))
 		 (const_string "V4SF")
-	       (ior (not (match_test "TARGET_SSE2"))
-		    (match_test "optimize_function_for_size_p (cfun)"))
-		 (const_string "V4SF")
 	       ]
 	       (const_string "TI")))])
 
@@ -3541,14 +3530,13 @@ 
 
 	       /* xorps is one byte shorter for non-AVX targets.  */
 	       (eq_attr "alternative" "12,16")
-		 (cond [(not (match_test "TARGET_SSE2"))
-		 	  (const_string "V4SF")
-			(and (match_test "TARGET_AVX512F")
-			  (not (match_test "TARGET_PREFER_AVX256")))
+		 (cond [(and (match_test "TARGET_AVX512F")
+			     (not (match_test "TARGET_PREFER_AVX256")))
 			  (const_string "XI")
 			(match_test "TARGET_AVX")
 			  (const_string "V2DF")
-			(match_test "optimize_function_for_size_p (cfun)")
+			(ior (not (match_test "TARGET_SSE2"))
+			     (match_test "optimize_function_for_size_p (cfun)"))
 			  (const_string "V4SF")
 			(match_test "TARGET_SSE_LOAD0_BY_PXOR")
 			  (const_string "TI")
@@ -3566,15 +3554,15 @@ 
 			     (ior (match_operand 0 "ext_sse_reg_operand")
 				  (match_operand 1 "ext_sse_reg_operand")))
 			  (const_string "V8DF")
+			(match_test "TARGET_AVX")
+			  (const_string "DF")
 			(ior (not (match_test "TARGET_SSE2"))
-			     (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
+			     (match_test "optimize_function_for_size_p (cfun)"))
+			  (const_string "V4SF")
+			(match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
 			  (const_string "V4SF")
 			(match_test "TARGET_SSE_PARTIAL_REG_DEPENDENCY")
 			  (const_string "V2DF")
-			(match_test "TARGET_AVX")
-			  (const_string "DF")
-			(match_test "optimize_function_for_size_p (cfun)")
-			  (const_string "V4SF")
 		       ]
 		       (const_string "DF"))
 
@@ -3723,16 +3711,15 @@ 
 	       (eq_attr "alternative" "11")
 		 (const_string "DI")
 	       (eq_attr "alternative" "5")
-		 (cond [(not (match_test "TARGET_SSE2"))
- 		 	  (const_string "V4SF")
-			(and (match_test "TARGET_AVX512F")
-			  (not (match_test "TARGET_PREFER_AVX256")))
+		 (cond [(and (match_test "TARGET_AVX512F")
+			     (not (match_test "TARGET_PREFER_AVX256")))
 			  (const_string "V16SF")
 			(match_test "TARGET_AVX")
 			  (const_string "V4SF")
- 			(match_test "optimize_function_for_size_p (cfun)")
+			(ior (not (match_test "TARGET_SSE2"))
+			     (match_test "optimize_function_for_size_p (cfun)"))
 			  (const_string "V4SF")
- 			(match_test "TARGET_SSE_LOAD0_BY_PXOR")
+			(match_test "TARGET_SSE_LOAD0_BY_PXOR")
 			  (const_string "TI")
 		       ]
 		       (const_string "V4SF"))
diff --git a/gcc/config/i386/mmx.md b/gcc/config/i386/mmx.md
index d06e3b1fcb49..f695831b5b90 100644
--- a/gcc/config/i386/mmx.md
+++ b/gcc/config/i386/mmx.md
@@ -195,11 +195,7 @@ 
 		     (match_test "<MODE>mode == V2SFmode")
 		       (const_string "V4SF")
 		     (ior (not (match_test "TARGET_SSE2"))
-			  (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		       (const_string "V4SF")
-		     (match_test "TARGET_AVX")
-		       (const_string "TI")
-		     (match_test "optimize_function_for_size_p (cfun)")
+			  (match_test "optimize_function_for_size_p (cfun)"))
 		       (const_string "V4SF")
 		    ]
 		    (const_string "TI"))
diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index abbd879aab35..91ef86ae274b 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -1118,13 +1118,15 @@ 
 		 (const_string "<sseinsnmode>")
 	       (match_test "TARGET_AVX")
 		 (const_string "<sseinsnmode>")
-	       (ior (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
-		    (and (eq_attr "alternative" "3")
-			 (match_test "TARGET_SSE_TYPELESS_STORES")))
-		 (const_string "<ssePSmode>")
 	       (ior (not (match_test "TARGET_SSE2"))
 		    (match_test "optimize_function_for_size_p (cfun)"))
 		 (const_string "V4SF")
+	       (and (match_test "<MODE>mode == V2DFmode")
+		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
+		 (const_string "V4SF")
+	       (and (eq_attr "alternative" "3")
+		    (match_test "TARGET_SSE_TYPELESS_STORES"))
+		 (const_string "V4SF")
 	       (and (eq_attr "alternative" "0")
 		    (match_test "TARGET_SSE_LOAD0_BY_PXOR"))
 		 (const_string "TI")
@@ -3555,16 +3557,14 @@ 
 		 (const_string "<sseintvecmode2>")
 	       (eq_attr "alternative" "3")
 		 (const_string "<sseintvecmode2>")
-	       (and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "<ssePSmode>")
 	       (match_test "TARGET_AVX")
 		 (const_string "<MODE>")
 	       (match_test "optimize_function_for_size_p (cfun)")
 		 (const_string "V4SF")
-	       ]
-	       (const_string "<MODE>")))])
-
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "<MODE>")))])
 
 (define_insn "<sse>_andnot<mode>3<mask_name>"
   [(set (match_operand:VF_512 0 "register_operand" "=v")
@@ -3673,15 +3673,14 @@ 
 		 (const_string "<sseintvecmode2>")
 	       (eq_attr "alternative" "3")
 		 (const_string "<sseintvecmode2>")
-	       (and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "<ssePSmode>")
 	       (match_test "TARGET_AVX")
 		 (const_string "<MODE>")
 	       (match_test "optimize_function_for_size_p (cfun)")
 		 (const_string "V4SF")
-	       ]
-	       (const_string "<MODE>")))])
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "<MODE>")))])
 
 (define_insn "*<code><mode>3<mask_name>"
   [(set (match_operand:VF_512 0 "register_operand" "=v")
@@ -3822,15 +3821,14 @@ 
 		 (if_then_else (match_test "TARGET_AVX512DQ")
 			       (const_string "<avx512fvecmode>")
 			       (const_string "XI"))
-	       (and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "V4SF")
 	       (match_test "TARGET_AVX")
 		 (const_string "<ssevecmode>")
 	       (match_test "optimize_function_for_size_p (cfun)")
 		 (const_string "V4SF")
-	       ]
-	       (const_string "<ssevecmode>")))])
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "<ssevecmode>")))])
 
 (define_insn "*andnottf3"
   [(set (match_operand:TF 0 "register_operand" "=x,x,v,v")
@@ -3879,15 +3877,15 @@ 
 		 (const_string "TI")
 	       (eq_attr "alternative" "3")
 		 (const_string "XI")
-	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
-		 (const_string "V4SF")
 	       (match_test "TARGET_AVX")
 		 (const_string "TI")
 	       (ior (not (match_test "TARGET_SSE2"))
 		    (match_test "optimize_function_for_size_p (cfun)"))
 		 (const_string "V4SF")
-	       ]
-	       (const_string "TI")))])
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "TI")))])
 
 (define_insn "*<code><mode>3"
   [(set (match_operand:MODEF 0 "register_operand" "=x,x,v,v")
@@ -3946,15 +3944,14 @@ 
 		 (if_then_else (match_test "TARGET_AVX512DQ")
 			       (const_string "<avx512fvecmode>")
 			       (const_string "XI"))
-	       (and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "V4SF")
 	       (match_test "TARGET_AVX")
 		 (const_string "<ssevecmode>")
 	       (match_test "optimize_function_for_size_p (cfun)")
 		 (const_string "V4SF")
-	       ]
-	       (const_string "<ssevecmode>")))])
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "<ssevecmode>")))])
 
 (define_expand "<code>tf3"
   [(set (match_operand:TF 0 "register_operand")
@@ -4011,15 +4008,15 @@ 
 		 (const_string "TI")
 	       (eq_attr "alternative" "3")
 		 (const_string "QI")
-	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
-		 (const_string "V4SF")
 	       (match_test "TARGET_AVX")
 		 (const_string "TI")
 	       (ior (not (match_test "TARGET_SSE2"))
 		    (match_test "optimize_function_for_size_p (cfun)"))
 		 (const_string "V4SF")
-	       ]
-	       (const_string "TI")))])
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "TI")))])
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -13007,10 +13004,7 @@ 
        (const_string "*")))
    (set_attr "prefix" "orig,vex,evex")
    (set (attr "mode")
-	(cond [(and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "<ssePSmode>")
-	       (match_test "TARGET_AVX2")
+	(cond [(match_test "TARGET_AVX2")
 		 (const_string "<sseinsnmode>")
 	       (match_test "TARGET_AVX")
 		 (if_then_else
@@ -13148,10 +13142,7 @@ 
        (const_string "*")))
    (set_attr "prefix" "<mask_prefix3>,evex")
    (set (attr "mode")
-	(cond [(and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "<ssePSmode>")
-	       (match_test "TARGET_AVX2")
+	(cond [(match_test "TARGET_AVX2")
 		 (const_string "<sseinsnmode>")
 	       (match_test "TARGET_AVX")
 		 (if_then_else
@@ -13244,10 +13235,7 @@ 
        (const_string "*")))
    (set_attr "prefix" "orig,vex,evex")
    (set (attr "mode")
-	(cond [(and (match_test "<MODE_SIZE> == 16")
-		    (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL"))
-		 (const_string "<ssePSmode>")
-	       (match_test "TARGET_AVX2")
+	(cond [(match_test "TARGET_AVX2")
 		 (const_string "<sseinsnmode>")
 	       (match_test "TARGET_AVX")
 		 (if_then_else
@@ -17151,14 +17139,14 @@ 
    (set_attr "prefix" "orig,orig,vex")
    (set_attr "btver2_decode" "vector,vector,vector") 
    (set (attr "mode")
-	(cond [(match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
-		 (const_string "V4SF")
-	       (match_test "TARGET_AVX")
+	(cond [(match_test "TARGET_AVX")
 		 (const_string "<ssevecmode>")
 	       (match_test "optimize_function_for_size_p (cfun)")
 		 (const_string "V4SF")
-	       ]
-	       (const_string "<ssevecmode>")))])
+	       (match_test "TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL")
+		 (const_string "V4SF")
+	      ]
+	      (const_string "<ssevecmode>")))])
 
 (define_insn_and_split "*<sse4_1>_blendv<ssemodesuffix><avxsizesuffix>_lt"
   [(set (match_operand:VF_128_256 0 "register_operand" "=Yr,*x,x")
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index 212547405a3f..d55687aa9e27 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -373,8 +373,8 @@  DEF_TUNE (X86_TUNE_SSE_UNALIGNED_STORE_OPTIMAL, "sse_unaligned_store_optimal",
 	  | m_INTEL | m_GOLDMONT | m_GOLDMONT_PLUS
 	  | m_TREMONT | m_BDVER | m_ZNVER | m_GENERIC)
 
-/* Use packed single precision instructions where posisble.  I.e. movups instead
-   of movupd.  */
+/* X86_TUNE_SSE_PACKED_SINGLE_INSN_OPTIMAL: Use packed single
+   precision 128bit instructions instead of double where possible.   */
 DEF_TUNE (X86_TUNE_SSE_PACKED_SINGLE_INSN_OPTIMAL, "sse_packed_single_insn_optimal",
 	  m_BDVER | m_ZNVER)