Re: [Patch] Request for comments: short int builtins

[Richard Biener <richard dot guenther at gmail dot com>]

On May 20, 2018 11:01:54 AM GMT+02:00, Allan Sandfeld Jensen <linux@carewolf.com> wrote:
>A little over a year back we had a regression in a point release of gcc
>
>because the builtin __builtin_clzs got removed from i386, in part
>because it 
>is was wrongly named for a target specific builtin, but we were using
>it in Qt 
>since it existed in multiple compilers. I got the patch removing it
>partially 
>reverted and the problem solved, but in the meantime I had worked on a
>patch 
>to make it a generic builtin instead. I have rebased it and added it
>below, 
>should I clean it up futher, finish the other builtins add tests and
>propose 
>it, or is this not something we want?

Can't users simply do clz((unsigned short) s) - 16? GCC should be able to handle this for instruction selection
With The addition of some folding patterns using the corresponding internal function. 

Richard. 

>diff --git a/gcc/builtin-types.def b/gcc/builtin-types.def
>index 5365befd351..74a84e653e4 100644
>--- a/gcc/builtin-types.def
>+++ b/gcc/builtin-types.def
>@@ -232,6 +232,8 @@ DEF_FUNCTION_TYPE_1 (BT_FN_INT_LONG, BT_INT,
>BT_LONG)
> DEF_FUNCTION_TYPE_1 (BT_FN_INT_ULONG, BT_INT, BT_ULONG)
> DEF_FUNCTION_TYPE_1 (BT_FN_INT_LONGLONG, BT_INT, BT_LONGLONG)
> DEF_FUNCTION_TYPE_1 (BT_FN_INT_ULONGLONG, BT_INT, BT_ULONGLONG)
>+DEF_FUNCTION_TYPE_1 (BT_FN_INT_INT16, BT_INT, BT_INT16)
>+DEF_FUNCTION_TYPE_1 (BT_FN_INT_UINT16, BT_INT, BT_UINT16)
> DEF_FUNCTION_TYPE_1 (BT_FN_INT_INTMAX, BT_INT, BT_INTMAX)
> DEF_FUNCTION_TYPE_1 (BT_FN_INT_UINTMAX, BT_INT, BT_UINTMAX)
> DEF_FUNCTION_TYPE_1 (BT_FN_INT_PTR, BT_INT, BT_PTR)
>diff --git a/gcc/builtins.c b/gcc/builtins.c
>index 9a2bf8c7d38..a8ad00e8016 100644
>--- a/gcc/builtins.c
>+++ b/gcc/builtins.c
>@@ -10689,14 +10689,17 @@ is_inexpensive_builtin (tree decl)
>       case BUILT_IN_CLZIMAX:
>       case BUILT_IN_CLZL:
>       case BUILT_IN_CLZLL:
>+      case BUILT_IN_CLZS:
>       case BUILT_IN_CTZ:
>       case BUILT_IN_CTZIMAX:
>       case BUILT_IN_CTZL:
>       case BUILT_IN_CTZLL:
>+      case BUILT_IN_CTZS:
>       case BUILT_IN_FFS:
>       case BUILT_IN_FFSIMAX:
>       case BUILT_IN_FFSL:
>       case BUILT_IN_FFSLL:
>+      case BUILT_IN_FFSS:
>       case BUILT_IN_IMAXABS:
>       case BUILT_IN_FINITE:
>       case BUILT_IN_FINITEF:
>@@ -10734,10 +10737,12 @@ is_inexpensive_builtin (tree decl)
>       case BUILT_IN_POPCOUNTL:
>       case BUILT_IN_POPCOUNTLL:
>       case BUILT_IN_POPCOUNTIMAX:
>+      case BUILT_IN_POPCOUNTS:
>       case BUILT_IN_POPCOUNT:
>       case BUILT_IN_PARITYL:
>       case BUILT_IN_PARITYLL:
>       case BUILT_IN_PARITYIMAX:
>+      case BUILT_IN_PARITYS:
>       case BUILT_IN_PARITY:
>       case BUILT_IN_LABS:
>       case BUILT_IN_LLABS:
>diff --git a/gcc/builtins.def b/gcc/builtins.def
>index 449d08d682f..618ee798767 100644
>--- a/gcc/builtins.def
>+++ b/gcc/builtins.def
>@@ -848,15 +848,18 @@ DEF_GCC_BUILTIN        (BUILT_IN_CLZ, "clz", 
>BT_FN_INT_UINT, ATTR_CONST_NOTHROW_
>DEF_GCC_BUILTIN        (BUILT_IN_CLZIMAX, "clzimax", BT_FN_INT_UINTMAX,
>
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CLZL, "clzl", BT_FN_INT_ULONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CLZLL, "clzll", BT_FN_INT_ULONGLONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>+DEF_GCC_BUILTIN        (BUILT_IN_CLZS, "clzs", BT_FN_INT_UINT16, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_CONSTANT_P, "constant_p",
>BT_FN_INT_VAR, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CTZ, "ctz", BT_FN_INT_UINT, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_CTZIMAX, "ctzimax", BT_FN_INT_UINTMAX,
>
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CTZL, "ctzl", BT_FN_INT_ULONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CTZLL, "ctzll", BT_FN_INT_ULONGLONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>+DEF_GCC_BUILTIN        (BUILT_IN_CTZS, "ctzs", BT_FN_INT_UINT16, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CLRSB, "clrsb", BT_FN_INT_INT, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_CLRSBIMAX, "clrsbimax",
>BT_FN_INT_INTMAX, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_CLRSBL, "clrsbl", BT_FN_INT_LONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_CLRSBLL, "clrsbll",
>BT_FN_INT_LONGLONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>+DEF_GCC_BUILTIN        (BUILT_IN_CLRSBS, "clrsbs", BT_FN_INT_INT16, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_EXT_LIB_BUILTIN    (BUILT_IN_DCGETTEXT, "dcgettext", 
>BT_FN_STRING_CONST_STRING_CONST_STRING_INT, ATTR_FORMAT_ARG_2)
> DEF_EXT_LIB_BUILTIN    (BUILT_IN_DGETTEXT, "dgettext", 
>BT_FN_STRING_CONST_STRING_CONST_STRING, ATTR_FORMAT_ARG_2)
> DEF_GCC_BUILTIN        (BUILT_IN_DWARF_CFA, "dwarf_cfa", BT_FN_PTR, 
>ATTR_NULL)
>@@ -878,6 +881,7 @@ DEF_EXT_LIB_BUILTIN    (BUILT_IN_FFS, "ffs", 
>BT_FN_INT_INT, ATTR_CONST_NOTHROW_L
>DEF_EXT_LIB_BUILTIN    (BUILT_IN_FFSIMAX, "ffsimax", BT_FN_INT_INTMAX, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_EXT_LIB_BUILTIN    (BUILT_IN_FFSL, "ffsl", BT_FN_INT_LONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_EXT_LIB_BUILTIN    (BUILT_IN_FFSLL, "ffsll", BT_FN_INT_LONGLONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>+DEF_EXT_LIB_BUILTIN    (BUILT_IN_FFSS, "ffss", BT_FN_INT_INT16, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_EXT_LIB_BUILTIN        (BUILT_IN_FORK, "fork", BT_FN_PID, 
>ATTR_NOTHROW_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_FRAME_ADDRESS, "frame_address", 
>BT_FN_PTR_UINT, ATTR_NULL)
>/* [trans-mem]: Adjust BUILT_IN_TM_FREE if BUILT_IN_FREE is changed. 
>*/
>@@ -924,10 +928,12 @@ DEF_GCC_BUILTIN        (BUILT_IN_PARITY,
>"parity", 
>BT_FN_INT_UINT, ATTR_CONST_NO
>DEF_GCC_BUILTIN        (BUILT_IN_PARITYIMAX, "parityimax",
>BT_FN_INT_UINTMAX, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_PARITYL, "parityl", BT_FN_INT_ULONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_PARITYLL, "parityll",
>BT_FN_INT_ULONGLONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
>+DEF_GCC_BUILTIN        (BUILT_IN_PARITYS, "paritys", BT_FN_INT_UINT16,
>
>ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_POPCOUNT, "popcount", BT_FN_INT_UINT, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_POPCOUNTIMAX, "popcountimax", 
>BT_FN_INT_UINTMAX, ATTR_CONST_NOTHROW_LEAF_LIST)
>DEF_GCC_BUILTIN        (BUILT_IN_POPCOUNTL, "popcountl",
>BT_FN_INT_ULONG, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_GCC_BUILTIN        (BUILT_IN_POPCOUNTLL, "popcountll", 
>BT_FN_INT_ULONGLONG, ATTR_CONST_NOTHROW_LEAF_LIST)
>+DEF_GCC_BUILTIN        (BUILT_IN_POPCOUNTS, "popcounts",
>BT_FN_INT_UINT16, 
>ATTR_CONST_NOTHROW_LEAF_LIST)
> DEF_EXT_LIB_BUILTIN    (BUILT_IN_POSIX_MEMALIGN, "posix_memalign", 
>BT_FN_INT_PTRPTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> DEF_GCC_BUILTIN        (BUILT_IN_PREFETCH, "prefetch", 
>BT_FN_VOID_CONST_PTR_VAR, ATTR_NOVOPS_LEAF_LIST)
>DEF_LIB_BUILTIN        (BUILT_IN_REALLOC, "realloc",
>BT_FN_PTR_PTR_SIZE, 
>ATTR_ALLOC_SIZE_2_NOTHROW_LEAF_LIST)
>diff --git a/gcc/config/i386/i386-builtin.def b/gcc/config/i386/i386-
>builtin.def
>index 1b9c63a16db..2fb5f3000ed 100644
>--- a/gcc/config/i386/i386-builtin.def
>+++ b/gcc/config/i386/i386-builtin.def
>@@ -1228,8 +1228,6 @@ BDESC (OPTION_MASK_ISA_AVX2,
>CODE_FOR_avx2_lshrvv4si, 
>"__builtin_ia32_psrlv4si",
> 
> /* LZCNT */
>BDESC (OPTION_MASK_ISA_LZCNT, CODE_FOR_lzcnt_hi,
>"__builtin_ia32_lzcnt_u16", 
>IX86_BUILTIN_LZCNT16, UNKNOWN, (int) UINT16_FTYPE_UINT16)
>-/* Same as above, for backward compatibility.  */
>-BDESC (OPTION_MASK_ISA_LZCNT, CODE_FOR_lzcnt_hi, "__builtin_clzs", 
>IX86_BUILTIN_CLZS, UNKNOWN, (int) UINT16_FTYPE_UINT16)
>BDESC (OPTION_MASK_ISA_LZCNT, CODE_FOR_lzcnt_si,
>"__builtin_ia32_lzcnt_u32", 
>IX86_BUILTIN_LZCNT32, UNKNOWN, (int) UINT_FTYPE_UINT)
>BDESC (OPTION_MASK_ISA_LZCNT | OPTION_MASK_ISA_64BIT,
>CODE_FOR_lzcnt_di, 
>"__builtin_ia32_lzcnt_u64", IX86_BUILTIN_LZCNT64, UNKNOWN, (int) 
>UINT64_FTYPE_UINT64)
> 
>@@ -1238,8 +1236,6 @@ BDESC (OPTION_MASK_ISA_BMI,
>CODE_FOR_bmi_bextr_si, 
>"__builtin_ia32_bextr_u32", I
>BDESC (OPTION_MASK_ISA_BMI | OPTION_MASK_ISA_64BIT,
>CODE_FOR_bmi_bextr_di, 
>"__builtin_ia32_bextr_u64", IX86_BUILTIN_BEXTR64, UNKNOWN, (int) 
>UINT64_FTYPE_UINT64_UINT64)
> 
>BDESC (OPTION_MASK_ISA_BMI, CODE_FOR_tzcnt_hi,
>"__builtin_ia32_tzcnt_u16", 
>IX86_BUILTIN_TZCNT16, UNKNOWN, (int) UINT16_FTYPE_UINT16)
>-/* Same as above, for backward compatibility.  */
>-BDESC (OPTION_MASK_ISA_BMI, CODE_FOR_tzcnt_hi, "__builtin_ctzs", 
>IX86_BUILTIN_CTZS, UNKNOWN, (int) UINT16_FTYPE_UINT16)
>BDESC (OPTION_MASK_ISA_BMI, CODE_FOR_tzcnt_si,
>"__builtin_ia32_tzcnt_u32", 
>IX86_BUILTIN_TZCNT32, UNKNOWN, (int) UINT_FTYPE_UINT)
>BDESC (OPTION_MASK_ISA_BMI | OPTION_MASK_ISA_64BIT, CODE_FOR_tzcnt_di, 
>"__builtin_ia32_tzcnt_u64", IX86_BUILTIN_TZCNT64, UNKNOWN, (int) 
>UINT64_FTYPE_UINT64)
> 
>diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>index 184b721dbf3..4c65c16b91d 100644
>--- a/gcc/config/i386/i386.c
>+++ b/gcc/config/i386/i386.c
>@@ -33430,7 +33430,6 @@ ix86_fold_builtin (tree fndecl, int n_args,
> 	  }
> 
> 	case IX86_BUILTIN_TZCNT16:
>-	case IX86_BUILTIN_CTZS:
> 	case IX86_BUILTIN_TZCNT32:
> 	case IX86_BUILTIN_TZCNT64:
> 	  gcc_assert (n_args == 1);
>@@ -33438,8 +33437,7 @@ ix86_fold_builtin (tree fndecl, int n_args,
> 	    {
> 	      tree type = TREE_TYPE (TREE_TYPE (fndecl));
> 	      tree arg = args[0];
>-	      if (fn_code == IX86_BUILTIN_TZCNT16
>-		  || fn_code == IX86_BUILTIN_CTZS)
>+	      if (fn_code == IX86_BUILTIN_TZCNT16)
> 		arg = fold_convert (short_unsigned_type_node, arg);
> 	      if (integer_zerop (arg))
> 		return build_int_cst (type, TYPE_PRECISION (TREE_TYPE (arg)));
>@@ -33449,7 +33447,6 @@ ix86_fold_builtin (tree fndecl, int n_args,
> 	  break;
> 
> 	case IX86_BUILTIN_LZCNT16:
>-	case IX86_BUILTIN_CLZS:
> 	case IX86_BUILTIN_LZCNT32:
> 	case IX86_BUILTIN_LZCNT64:
> 	  gcc_assert (n_args == 1);
>@@ -33457,8 +33454,7 @@ ix86_fold_builtin (tree fndecl, int n_args,
> 	    {
> 	      tree type = TREE_TYPE (TREE_TYPE (fndecl));
> 	      tree arg = args[0];
>-	      if (fn_code == IX86_BUILTIN_LZCNT16
>-		  || fn_code == IX86_BUILTIN_CLZS)
>+	      if (fn_code == IX86_BUILTIN_LZCNT16)
> 		arg = fold_convert (short_unsigned_type_node, arg);
> 	      if (integer_zerop (arg))
> 		return build_int_cst (type, TYPE_PRECISION (TREE_TYPE (arg)));
>@@ -33867,6 +33863,10 @@ ix86_gimple_fold_builtin (gimple_stmt_iterator
>*gsi)
> 
>   switch (fn_code)
>     {
>+    case IX86_BUILTIN_TZCNT16:
>+      decl = builtin_decl_implicit (BUILT_IN_CTZS);
>+      goto fold_tzcnt_lzcnt;
>+
>     case IX86_BUILTIN_TZCNT32:
>       decl = builtin_decl_implicit (BUILT_IN_CTZ);
>       goto fold_tzcnt_lzcnt;
>@@ -33875,6 +33875,10 @@ ix86_gimple_fold_builtin (gimple_stmt_iterator
>*gsi)
>       decl = builtin_decl_implicit (BUILT_IN_CTZLL);
>       goto fold_tzcnt_lzcnt;
> 
>+    case IX86_BUILTIN_LZCNT16:
>+      decl = builtin_decl_implicit (BUILT_IN_CLZS);
>+      goto fold_tzcnt_lzcnt;
>+
>     case IX86_BUILTIN_LZCNT32:
>       decl = builtin_decl_implicit (BUILT_IN_CLZ);
>       goto fold_tzcnt_lzcnt;
>diff --git a/gcc/gencfn-macros.c b/gcc/gencfn-macros.c
>index 28f7b6f7298..d2edceb0a2e 100644
>--- a/gcc/gencfn-macros.c
>+++ b/gcc/gencfn-macros.c
>@@ -160,7 +160,7 @@ static const char *const fltfn_suffixes[] = {
>"F16", 
>"F32", "F64", "F128",
>static const char *const fltall_suffixes[] = { "F", "", "L", "F16",
>"F32",
> 					       "F64", "F128", "F32X", "F64X",
> 					       "F128X", NULL };
>-static const char *const int_suffixes[] = { "", "L", "LL", "IMAX",
>NULL };
>+static const char *const int_suffixes[] = { "", "L", "LL", "S",
>"IMAX", NULL 
>};
> 
> static const char *const *const suffix_lists[] = {
>   flt_suffixes,
>diff --git a/gcc/hsa-gen.c b/gcc/hsa-gen.c
>index 74d5f07b3cb..00f783b883d 100644
>--- a/gcc/hsa-gen.c
>+++ b/gcc/hsa-gen.c
>@@ -5390,12 +5390,14 @@ gen_hsa_insns_for_call (gimple *stmt, hsa_bb
>*hbb)
>     case BUILT_IN_CLZ:
>     case BUILT_IN_CLZL:
>     case BUILT_IN_CLZLL:
>+    case BUILT_IN_CLZS:
>       gen_hsa_unaryop_for_builtin (BRIG_OPCODE_FIRSTBIT, stmt, hbb);
>       break;
> 
>     case BUILT_IN_CTZ:
>     case BUILT_IN_CTZL:
>     case BUILT_IN_CTZLL:
>+    case BUILT_IN_CTZS:
>       gen_hsa_unaryop_for_builtin (BRIG_OPCODE_LASTBIT, stmt, hbb);
>       break;
> 
>diff --git a/gcc/tree.h b/gcc/tree.h
>index ef8bff405fe..9b43238eebf 100644
>--- a/gcc/tree.h
>+++ b/gcc/tree.h
>@@ -217,7 +217,7 @@ as_internal_fn (combined_fn code)
>   case FN##F16: case FN##F32: case FN##F64: case FN##F128: \
>   case FN##F32X: case FN##F64X: case FN##F128X
> #define CASE_FLT_FN_REENT(FN) case FN##_R: case FN##F_R: case FN##L_R
>-#define CASE_INT_FN(FN) case FN: case FN##L: case FN##LL: case
>FN##IMAX
>+#define CASE_INT_FN(FN) case FN: case FN##L: case FN##LL: case FN##S:
>case 
>FN##IMAX
> 
> #define NULL_TREE (tree) NULL
>