Don't generate unnecessary let $arg=$arg for intrinsics

Author: bjorn3

src/intrinsics/llvm.rs

@@ -52,8 +52,8 @@ pub(crate) fn codegen_llvm_intrinsic_call<'tcx>(
             ret.write_cvalue(fx, res);
         };
         "llvm.x86.sse2.cmp.ps" | "llvm.x86.sse2.cmp.pd", (c x, c y, o kind) {
-            let kind_const = crate::constant::mir_operand_get_const_val(fx, kind).expect("llvm.x86.sse2.cmp.* kind not const");
-            let flt_cc = match kind_const.try_to_bits(Size::from_bytes(1)).unwrap_or_else(|| panic!("kind not scalar: {:?}", kind_const)) {
+            let kind = crate::constant::mir_operand_get_const_val(fx, kind).expect("llvm.x86.sse2.cmp.* kind not const");
+            let flt_cc = match kind.try_to_bits(Size::from_bytes(1)).unwrap_or_else(|| panic!("kind not scalar: {:?}", kind)) {
                 0 => FloatCC::Equal,
                 1 => FloatCC::LessThan,
                 2 => FloatCC::LessThanOrEqual,

src/intrinsics/mod.rs

@@ -31,14 +31,12 @@ macro intrinsic_pat {
 }
 
 macro intrinsic_arg {
-    (o $fx:expr, $arg:ident) => {
-        $arg
-    },
+    (o $fx:expr, $arg:ident) => {},
     (c $fx:expr, $arg:ident) => {
-        codegen_operand($fx, $arg)
+        let $arg = codegen_operand($fx, $arg);
     },
     (v $fx:expr, $arg:ident) => {
-        codegen_operand($fx, $arg).load_scalar($fx)
+        let $arg = codegen_operand($fx, $arg).load_scalar($fx);
     }
 }
 
@@ -52,9 +50,7 @@ macro intrinsic_match {
             $(
                 $(intrinsic_pat!($($name).*))|* $(if $cond)? => {
                     if let [$($arg),*] = $args {
-                        let ($($arg,)*) = (
-                            $(intrinsic_arg!($a $fx, $arg),)*
-                        );
+                        $(intrinsic_arg!($a $fx, $arg);)*
                         $content
                     } else {
                         bug!("wrong number of args for intrinsic {:?}", $intrinsic);