agx: Add agx_immediate_f helper

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11718>

src/asahi/compiler/agx_compiler.h

@@ -31,6 +31,7 @@
 #include "util/u_dynarray.h"
 #include "agx_compile.h"
 #include "agx_opcodes.h"
+#include "agx_minifloat.h"
 
 enum agx_dbg {
    AGX_DBG_MSGS        = BITFIELD_BIT(0),
@@ -92,6 +93,13 @@ agx_immediate(uint16_t imm)
    };
 }
 
+static inline agx_index
+agx_immediate_f(float f)
+{
+   assert(agx_minifloat_exact(f));
+   return agx_immediate(agx_minifloat_encode(f));
+}
+
 /* in half-words, specify r0h as 1, r1 as 2... */
 static inline agx_index
 agx_register(uint8_t imm, enum agx_size size)