[libspirv] Define schar overloads via remangling; not source (#18626)

We were previously achieving the signed char builtin definitions in
libspirv via one of two ways. The first was explicitly definining schar
overloads of builtins in the source. The second was by remangling 'char'
builtins to one of schar or uchar, depending on the host platform.

Since we are defining our builtins in OpenCL C, the plain 'char' type is
already a signed type. This presents us with the opportunity to achieve
our desired schar builtins solely through remangling. The primary idea
is to reduce our libclc/libspirv diff with upstream. We also have the
option to introduce signed char builtins upstream. As it stands the
schar problem isn't far from the 'half' mangling problem that we also
now deal with purely in the remangler.

Author: frasercrmck

clang/lib/Sema/SPIRVBuiltins.td

@@ -322,8 +322,7 @@ class ConstOCLSPVBuiltin<string _Name, list<Type> _Signature> :
 // OpenCL v1.0/1.2/2.0 s6.1.1: Built-in Scalar Data Types.
 def Bool      : IntType<"bool",   QualType<"Context.BoolTy">, 1>;
 def TrueChar  : IntType<"_char",      QualType<"Context.CharTy", 0, 1>, 8>;
-def Char      : IntType<"char",      QualType<"Context.SignedCharTy", 0, 1>, 8>;
-def SChar     : IntType<"schar",     QualType<"Context.SignedCharTy", 0, 1>, 8>;
+def Char      : IntType<"char",      QualTypeFromFunction<"GetCharType", 0, 1>, 8>;
 def UChar     : UIntType<"uchar",     QualType<"Context.UnsignedCharTy">, 8>;
 def Short     : IntType<"short",     QualType<"Context.ShortTy", 0, 1>, 16>;
 def UShort    : UIntType<"ushort",    QualType<"Context.UnsignedShortTy">, 16>;
@@ -412,7 +411,7 @@ def IntLongFloatGenType1   : GenericType<"IntLongFloatGenType1", TLIntLongFloats
 
 // GenType definitions for every single base type (e.g. fp32 only).
 // Names are like: GenTypeFloatVecAndScalar.
-foreach Type = [Char, UChar, SChar, Short, UShort,
+foreach Type = [Char, UChar, Short, UShort,
                 Int, UInt, Long, ULong,
                 Float, Double, Half] in {
   foreach VecSizes = [VecAndScalar, VecNoScalar] in {
@@ -872,16 +871,16 @@ foreach name = ["Dot"] in {
 }
 
 foreach name = ["Any", "All"] in {
-  def : SPVBuiltin<name, [Bool, GenTypeSCharVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [Bool, GenTypeCharVecNoScalar], Attr.Const>;
 }
 
 foreach name = ["IsNan", "IsInf", "IsFinite", "IsNormal", "SignBitSet"] in {
   def : SPVBuiltin<name, [Bool, Float], Attr.Const>;
   def : SPVBuiltin<name, [Bool, Double], Attr.Const>;
   def : SPVBuiltin<name, [Bool, Half], Attr.Const>;
-  def : SPVBuiltin<name, [GenTypeSCharVecNoScalar, GenTypeFloatVecNoScalar], Attr.Const>;
-  def : SPVBuiltin<name, [GenTypeSCharVecNoScalar, GenTypeDoubleVecNoScalar], Attr.Const>;
-  def : SPVBuiltin<name, [GenTypeSCharVecNoScalar, GenTypeHalfVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [GenTypeCharVecNoScalar, GenTypeFloatVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [GenTypeCharVecNoScalar, GenTypeDoubleVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [GenTypeCharVecNoScalar, GenTypeHalfVecNoScalar], Attr.Const>;
 }
 
 foreach name = ["LessOrGreater",
@@ -895,9 +894,9 @@ foreach name = ["LessOrGreater",
   def : SPVBuiltin<name, [Bool, Float, Float], Attr.Const>;
   def : SPVBuiltin<name, [Bool, Double, Double], Attr.Const>;
   def : SPVBuiltin<name, [Bool, Half, Half], Attr.Const>;
-  def : SPVBuiltin<name, [GenTypeSCharVecNoScalar, GenTypeFloatVecNoScalar, GenTypeFloatVecNoScalar], Attr.Const>;
-  def : SPVBuiltin<name, [GenTypeSCharVecNoScalar, GenTypeDoubleVecNoScalar, GenTypeDoubleVecNoScalar], Attr.Const>;
-  def : SPVBuiltin<name, [GenTypeSCharVecNoScalar, GenTypeHalfVecNoScalar, GenTypeHalfVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [GenTypeCharVecNoScalar, GenTypeFloatVecNoScalar, GenTypeFloatVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [GenTypeCharVecNoScalar, GenTypeDoubleVecNoScalar, GenTypeDoubleVecNoScalar], Attr.Const>;
+  def : SPVBuiltin<name, [GenTypeCharVecNoScalar, GenTypeHalfVecNoScalar, GenTypeHalfVecNoScalar], Attr.Const>;
 }
 
 foreach name = ["BitCount"] in {

clang/lib/Sema/SemaLookup.cpp

@@ -51,6 +51,7 @@
 #include <utility>
 #include <vector>
 
+static inline clang::QualType GetCharType(clang::ASTContext &Context);
 static inline clang::QualType GetFloat16Type(clang::ASTContext &Context);
 
 #include "OpenCLBuiltins.inc"
@@ -701,6 +702,10 @@ LLVM_DUMP_METHOD void LookupResult::dump() {
     D->dump();
 }
 
+static inline QualType GetCharType(clang::ASTContext &Context) {
+  return Context.getLangOpts().OpenCL ? Context.CharTy : Context.SignedCharTy;
+}
+
 static inline QualType GetFloat16Type(clang::ASTContext &Context) {
   return Context.getLangOpts().OpenCL ? Context.HalfTy : Context.Float16Ty;
 }

clang/test/CodeGenSPIRV/spirv-builtin-lookup-group.cl

@@ -27,7 +27,7 @@ bool group_any(bool predicate) {
 
 char group_broad_cast(char a) {
   // CHECK-LABEL: @group_broad_cast(
-  // CHECK: call spir_func i32 @_Z22__spirv_GroupBroadcastiij(
+  // CHECK: call spir_func signext i8 @_Z22__spirv_GroupBroadcasticj(
   return __spirv_GroupBroadcast(2, a, 0u);
 }
 
@@ -87,7 +87,7 @@ unsigned long group_umax(unsigned long a) {
 
 char group_smin(char a) {
   // CHECK-LABEL: @group_smin(
-  // CHECK: call spir_func i32 @_Z17__spirv_GroupSMiniii(
+  // CHECK: call spir_func signext i8 @_Z17__spirv_GroupSMiniic(
   return __spirv_GroupSMin(2, 0, a);
 }
 

libclc/clc/include/clc/clc_as_type.h

@@ -10,7 +10,6 @@
 #define __CLC_CLC_AS_TYPE_H__
 
 #define __clc_as_char(x) __builtin_astype(x, char)
-#define __clc_as_schar(x) __builtin_astype(x, schar)
 #define __clc_as_uchar(x) __builtin_astype(x, uchar)
 #define __clc_as_short(x) __builtin_astype(x, short)
 #define __clc_as_ushort(x) __builtin_astype(x, ushort)
@@ -21,7 +20,6 @@
 #define __clc_as_float(x) __builtin_astype(x, float)
 
 #define __clc_as_char2(x) __builtin_astype(x, char2)
-#define __clc_as_schar2(x) __builtin_astype(x, schar2)
 #define __clc_as_uchar2(x) __builtin_astype(x, uchar2)
 #define __clc_as_short2(x) __builtin_astype(x, short2)
 #define __clc_as_ushort2(x) __builtin_astype(x, ushort2)
@@ -32,7 +30,6 @@
 #define __clc_as_float2(x) __builtin_astype(x, float2)
 
 #define __clc_as_char3(x) __builtin_astype(x, char3)
-#define __clc_as_schar3(x) __builtin_astype(x, schar3)
 #define __clc_as_uchar3(x) __builtin_astype(x, uchar3)
 #define __clc_as_short3(x) __builtin_astype(x, short3)
 #define __clc_as_ushort3(x) __builtin_astype(x, ushort3)
@@ -43,7 +40,6 @@
 #define __clc_as_float3(x) __builtin_astype(x, float3)
 
 #define __clc_as_char4(x) __builtin_astype(x, char4)
-#define __clc_as_schar4(x) __builtin_astype(x, schar4)
 #define __clc_as_uchar4(x) __builtin_astype(x, uchar4)
 #define __clc_as_short4(x) __builtin_astype(x, short4)
 #define __clc_as_ushort4(x) __builtin_astype(x, ushort4)
@@ -54,9 +50,7 @@
 #define __clc_as_float4(x) __builtin_astype(x, float4)
 
 #define __clc_as_char8(x) __builtin_astype(x, char8)
-#define __clc_as_schar8(x) __builtin_astype(x, schar8)
 #define __clc_as_uchar8(x) __builtin_astype(x, uchar8)
-#define __clc_as_schar8(x) __builtin_astype(x, schar8)
 #define __clc_as_short8(x) __builtin_astype(x, short8)
 #define __clc_as_ushort8(x) __builtin_astype(x, ushort8)
 #define __clc_as_int8(x) __builtin_astype(x, int8)
@@ -66,7 +60,6 @@
 #define __clc_as_float8(x) __builtin_astype(x, float8)
 
 #define __clc_as_char16(x) __builtin_astype(x, char16)
-#define __clc_as_schar16(x) __builtin_astype(x, schar16)
 #define __clc_as_uchar16(x) __builtin_astype(x, uchar16)
 #define __clc_as_short16(x) __builtin_astype(x, short16)
 #define __clc_as_ushort16(x) __builtin_astype(x, ushort16)

libclc/clc/include/clc/clc_convert.h

@@ -24,7 +24,6 @@
 
 #define _CLC_VECTOR_CONVERT_FROM1(FROM_TYPE, SUFFIX)                           \
   _CLC_VECTOR_CONVERT_DECL(FROM_TYPE, char, SUFFIX)                            \
-  _CLC_VECTOR_CONVERT_DECL(FROM_TYPE, schar, SUFFIX)                           \
   _CLC_VECTOR_CONVERT_DECL(FROM_TYPE, uchar, SUFFIX)                           \
   _CLC_VECTOR_CONVERT_DECL(FROM_TYPE, int, SUFFIX)                             \
   _CLC_VECTOR_CONVERT_DECL(FROM_TYPE, uint, SUFFIX)                            \
@@ -58,7 +57,6 @@
 
 #define _CLC_VECTOR_CONVERT_TO1(SUFFIX)                                        \
   _CLC_VECTOR_CONVERT_FROM(char, SUFFIX)                                       \
-  _CLC_VECTOR_CONVERT_FROM(schar, SUFFIX)                                      \
   _CLC_VECTOR_CONVERT_FROM(uchar, SUFFIX)                                      \
   _CLC_VECTOR_CONVERT_FROM(int, SUFFIX)                                        \
   _CLC_VECTOR_CONVERT_FROM(uint, SUFFIX)                                       \

libclc/clc/include/clc/clctypes.h

@@ -11,7 +11,6 @@
 
 /* 6.1.1 Built-in Scalar Data Types */
 
-typedef signed char schar;
 typedef unsigned char uchar;
 typedef unsigned short ushort;
 typedef unsigned int uint;
@@ -40,12 +39,6 @@ typedef __attribute__((ext_vector_type(4))) char char4;
 typedef __attribute__((ext_vector_type(8))) char char8;
 typedef __attribute__((ext_vector_type(16))) char char16;
 
-typedef __attribute__((ext_vector_type(2))) schar schar2;
-typedef __attribute__((ext_vector_type(3))) schar schar3;
-typedef __attribute__((ext_vector_type(4))) schar schar4;
-typedef __attribute__((ext_vector_type(8))) schar schar8;
-typedef __attribute__((ext_vector_type(16))) schar schar16;
-
 typedef __attribute__((ext_vector_type(2))) uchar uchar2;
 typedef __attribute__((ext_vector_type(3))) uchar uchar3;
 typedef __attribute__((ext_vector_type(4))) uchar uchar4;