[llvm] [SPIRV] Use `Op[S|U]Dot` when possible for integer dot product (PR #115095)

[Greg Roth via llvm-commits]

================
@@ -73,16 +127,21 @@ define noundef i64 @dot_uint64_t4(<2 x i64> noundef %a, <2 x i64> noundef %b) {
 entry:
 ; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#vec2_int_64]]
 ; CHECK: %[[#arg1:]] = OpFunctionParameter %[[#vec2_int_64]]
-; CHECK: %[[#mul_vec:]] = OpIMul %[[#vec2_int_64]] %[[#arg0]] %[[#arg1]]
-; CHECK: %[[#elt0:]] = OpCompositeExtract %[[#int_64]] %[[#mul_vec]] 0
-; CHECK: %[[#elt1:]] = OpCompositeExtract %[[#int_64]] %[[#mul_vec]] 1
-; CHECK: %[[#sum0:]] = OpIAdd %[[#int_64]] %[[#elt0]] %[[#elt1]]
+
+; CHECK-DOT: %[[#dot:]] = OpUDot %[[#int_64]] %[[#arg0]] %[[#arg1]]
+
+; CHECK-EXP: %[[#mul_vec:]] = OpIMul %[[#vec2_int_64]] %[[#arg0]] %[[#arg1]]
+; CHECK-EXP: %[[#elt0:]] = OpCompositeExtract %[[#int_64]] %[[#mul_vec]] 0
+; CHECK-EXP: %[[#elt1:]] = OpCompositeExtract %[[#int_64]] %[[#mul_vec]] 1
+; CHECK-EXP: %[[#sum0:]] = OpIAdd %[[#int_64]] %[[#elt0]] %[[#elt1]]
   %dot = call i64 @llvm.spv.udot.v2i64(<2 x i64> %a, <2 x i64> %b)
   ret i64 %dot
 }
 
+declare i8 @llvm.spv.sdot.v4i8(<4 x i8>, <4 x i8>)
 declare i16 @llvm.spv.sdot.v2i16(<2 x i16>, <2 x i16>)
 declare i32 @llvm.spv.sdot.v4i32(<4 x i32>, <4 x i32>)
+declare i8 @llvm.spv.udot.v4i8(<4 x i8>, <4 x i8>)
----------------
pow2clk wrote:

It's inconsequential, but since these declarations are optional  and this list is missing some existing used functions anyway, we might just as well remove them all rather than add to the incomplete list. 

https://github.com/llvm/llvm-project/pull/115095