[WebAssembly] Support fp reg class in r constraint (#83)

Patch by snek

Reviewed By: aheejin

Differential Revision: https://reviews.llvm.org/D90978

Author: devsnek

llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

@@ -542,6 +542,16 @@ WebAssemblyTargetLowering::getRegForInlineAsmConstraint(
         if (VT.getSizeInBits() <= 64)
           return std::make_pair(0U, &WebAssembly::I64RegClass);
       }
+      if (VT.isFloatingPoint() && !VT.isVector()) {
+        switch (VT.getSizeInBits()) {
+        case 32:
+          return std::make_pair(0U, &WebAssembly::F32RegClass);
+        case 64:
+          return std::make_pair(0U, &WebAssembly::F64RegClass);
+        default:
+          break;
+        }
+      }
       break;
     default:
       break;

llvm/test/CodeGen/WebAssembly/inline-asm.ll

@@ -46,6 +46,32 @@ entry:
   ret i64 %0
 }
 
+; CHECK-LABEL: foo_float:
+; CHECK-NEXT: .functype foo_float (f32) -> (f32){{$}}
+; CHECK-NEXT: #APP{{$}}
+; CHECK-NEXT: # 0 = aaa(0){{$}}
+; CHECK-NEXT: #NO_APP{{$}}
+; CHECK-NEXT: local.get $push0=, 0{{$}}
+; CHECK-NEXT: return $pop0{{$}}
+define float @foo_float(float %r) {
+entry:
+  %0 = tail call float asm sideeffect "# $0 = aaa($1)", "=r,r"(float %r) #0, !srcloc !0
+  ret float %0
+}
+
+; CHECK-LABEL: foo_double:
+; CHECK-NEXT: .functype foo_double (f64) -> (f64){{$}}
+; CHECK-NEXT: #APP{{$}}
+; CHECK-NEXT: # 0 = aaa(0){{$}}
+; CHECK-NEXT: #NO_APP{{$}}
+; CHECK-NEXT: local.get $push0=, 0{{$}}
+; CHECK-NEXT: return $pop0{{$}}
+define double @foo_double(double %r) {
+entry:
+  %0 = tail call double asm sideeffect "# $0 = aaa($1)", "=r,r"(double %r) #0, !srcloc !0
+  ret double %0
+}
+
 ; CHECK-LABEL: X_i16:
 ; CHECK: foo 1{{$}}
 ; CHECK: local.get $push[[S0:[0-9]+]]=, 0{{$}}