[NVPTX] Support BFloat Store Parameter (#137074)

Before this patch, the instruction selector assumed that if the Memory
Type is not {f16, v2f16, f32, f64} then the node type must be a
ConstantSDNode when in fact if the memory type is bf16 then the node
type is ConstantFPSDNode.

Author: stumpOS

llvm/lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp

@@ -1868,7 +1868,7 @@ bool NVPTXDAGToDAGISel::tryStoreParam(SDNode *N) {
     case 1: {
       MVT::SimpleValueType MemTy = Mem->getMemoryVT().getSimpleVT().SimpleTy;
       SDValue Imm = Ops[0];
-      if (MemTy != MVT::f16 && MemTy != MVT::v2f16 &&
+      if (MemTy != MVT::f16 && MemTy != MVT::bf16 &&
           (isa<ConstantSDNode>(Imm) || isa<ConstantFPSDNode>(Imm))) {
         // Convert immediate to target constant
         if (MemTy == MVT::f32 || MemTy == MVT::f64) {

llvm/test/CodeGen/NVPTX/st-param-imm.ll

@@ -2000,3 +2000,27 @@ declare void @call_v4_i8(%struct.char4 alignstack(4))
 declare void @call_v4_i16(%struct.short4 alignstack(8))
 declare void @call_v4_i32(%struct.int4 alignstack(16))
 declare void @call_v4_f32(%struct.float4 alignstack(16))
+
+define void @st_param_bfloat() {
+; CHECK-LABEL: st_param_bfloat(
+; CHECK: {
+; CHECK-NEXT:	.reg .b16 	%rs<2>;
+; CHECK-EMPTY:
+; CHECK-NEXT:// %bb.0:
+; CHECK-NEXT:	mov.b16 	%rs1, 0x4100;
+; CHECK-NEXT:	{ // callseq 83, 0
+; CHECK-NEXT:	.param .align 2 .b8 param0[2];
+; CHECK-NEXT:	st.param.b16 	[param0], %rs1;
+; CHECK-NEXT:	call.uni
+; CHECK-NEXT:	call_bfloat,
+; CHECK-NEXT:	(
+; CHECK-NEXT:	param0
+; CHECK-NEXT:	);
+; CHECK-NEXT:	} // callseq 83
+; CHECK-NEXT:	ret;
+  %five = bitcast i16 16640 to bfloat
+  call void @call_bfloat(bfloat %five)
+  ret void
+}
+
+declare void @call_bfloat(bfloat)