[RISCV] Mark FLH as canFoldAsLoad. (#165974)

Author: topperc

llvm/lib/Target/RISCV/RISCVInstrInfoZfh.td

@@ -90,6 +90,7 @@ defvar ZfhminDExts = [ZfhminDExt, ZhinxminZdinxExt, ZhinxminZdinx32Ext];
 //===----------------------------------------------------------------------===//
 
 let Predicates = [HasHalfFPLoadStoreMove] in {
+let canFoldAsLoad = 1 in
 def FLH : FPLoad_r<0b001, "flh", FPR16, WriteFLD16>;
 
 // Operands for stores are in the order srcreg, base, offset rather than

llvm/test/CodeGen/RISCV/rv64-stackmap-fp.ll

@@ -0,0 +1,41 @@
+; RUN: llc -mtriple=riscv64 -mattr=+d,+zfh < %s | FileCheck %s
+
+; CHECK-LABEL:  .section	.llvm_stackmaps
+; CHECK-NEXT:  __LLVM_StackMaps:
+; Header
+; CHECK-NEXT:   .byte   3
+; CHECK-NEXT:   .byte   0
+; CHECK-NEXT:   .half   0
+; Num Functions
+; CHECK-NEXT:   .word   1
+; Num LargeConstants
+; CHECK-NEXT:   .word   0
+; Num Callsites
+; CHECK-NEXT:   .word   1
+
+; Functions and stack size
+; CHECK-NEXT:   .quad   liveArgs
+; CHECK-NEXT:   .quad   0
+; CHECK-NEXT:   .quad   1
+
+; Spilled stack map values.
+;
+; Verify 3 stack map entries.
+;
+; CHECK-LABEL:  .word   .L{{.*}}-liveArgs
+; CHECK-NEXT:   .half   0
+; CHECK-NEXT:   .half   25
+;
+; Check that at least one is a spilled entry from SP.
+; Location: Indirect SP + ...
+; CHECK:        .byte   3
+; CHECK-NEXT:   .byte   0
+; CHECK-NEXT:   .half   8
+; CHECK-NEXT:   .half   2
+; CHECK-NEXT:   .half   0
+; CHECK-NEXT:   .word
+define void @liveArgs(double %arg0, double %arg1, double %arg2, double %arg3, double %arg4, double %arg5, double %arg6, double %arg7, double %arg8, double %arg9, double %arg10, double %arg11, double %arg12, double %arg13, double %arg14, double %arg15, double %arg16, double %arg17, double %arg18, double %arg19, double %arg20, double %arg21, double %arg22, double %arg23, half %arg24, half %arg25, half %arg26, half %arg27, half %arg28, bfloat %arg29) {
+entry:
+  call void (i64, i32, ptr, i32, ...) @llvm.experimental.patchpoint.void(i64 11, i32 28, ptr null, i32 5, double %arg0, double %arg1, double %arg2, double %arg3, double %arg4, double %arg5, double %arg6, double %arg7, double %arg8, double %arg9, double %arg10, double %arg11, double %arg12, double %arg13, double %arg14, double %arg15, double %arg16, double %arg17, double %arg18, double %arg19, double %arg20, double %arg21, double %arg22, double %arg23, half %arg24, half %arg25, half %arg26, half %arg27, half %arg28, bfloat %arg29)
+  ret void
+}