From 54862c8a6b496fee208b2b7f48f9e446de52a3af Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@cs.stanford.edu>
Date: Sat, 10 Feb 2024 14:43:31 -0800
Subject: [PATCH] c-writer.cc: represent float consts as integer literals

---
 src/c-writer.cc            | 48 ++++----------------------------------
 test/wasm2c/tail-calls.txt |  4 ++--
 2 files changed, 7 insertions(+), 45 deletions(-)

diff --git a/src/c-writer.cc b/src/c-writer.cc
index d7a61f421..9dec2148c 100644
--- a/src/c-writer.cc
+++ b/src/c-writer.cc
@@ -1250,52 +1250,14 @@ void CWriter::Write(const Const& const_) {
       Writef("%" PRIu64 "ull", static_cast<int64_t>(const_.u64()));
       break;
 
-    case Type::F32: {
-      uint32_t f32_bits = const_.f32_bits();
-      // TODO(binji): Share with similar float info in interp.cc and literal.cc
-      if ((f32_bits & 0x7f800000u) == 0x7f800000u) {
-        const char* sign = (f32_bits & 0x80000000) ? "-" : "";
-        uint32_t significand = f32_bits & 0x7fffffu;
-        if (significand == 0) {
-          // Infinity.
-          Writef("%sINFINITY", sign);
-        } else {
-          // Nan.
-          Writef("f32_reinterpret_i32(0x%08x) /* %snan:0x%06x */", f32_bits,
-                 sign, significand);
-        }
-      } else if (f32_bits == 0x80000000) {
-        // Negative zero. Special-cased so it isn't written as -0 below.
-        Writef("-0.f");
-      } else {
-        Writef("%.9g", Bitcast<float>(f32_bits));
-      }
+    case Type::F32:
+      Writef("f32_reinterpret_i32(0x%" PRIx32 ")", const_.f32_bits());
       break;
-    }
 
-    case Type::F64: {
-      uint64_t f64_bits = const_.f64_bits();
-      // TODO(binji): Share with similar float info in interp.cc and literal.cc
-      if ((f64_bits & 0x7ff0000000000000ull) == 0x7ff0000000000000ull) {
-        const char* sign = (f64_bits & 0x8000000000000000ull) ? "-" : "";
-        uint64_t significand = f64_bits & 0xfffffffffffffull;
-        if (significand == 0) {
-          // Infinity.
-          Writef("%sINFINITY", sign);
-        } else {
-          // Nan.
-          Writef("f64_reinterpret_i64(0x%016" PRIx64 ") /* %snan:0x%013" PRIx64
-                 " */",
-                 f64_bits, sign, significand);
-        }
-      } else if (f64_bits == 0x8000000000000000ull) {
-        // Negative zero. Special-cased so it isn't written as -0 below.
-        Writef("-0.0");
-      } else {
-        Writef("%.17g", Bitcast<double>(f64_bits));
-      }
+    case Type::F64:
+      Writef("f64_reinterpret_i64(0x%" PRIx64 ")", const_.f64_bits());
       break;
-    }
+
     case Type::V128: {
       Writef("v128_const(0x%02x", const_.vec128().u8(0));
       for (int i = 1; i < 16; i++) {
diff --git a/test/wasm2c/tail-calls.txt b/test/wasm2c/tail-calls.txt
index fe9815e35..e3b51bbe2 100644
--- a/test/wasm2c/tail-calls.txt
+++ b/test/wasm2c/tail-calls.txt
@@ -823,7 +823,7 @@ void w2c_test_tailcaller_0(w2c_test* instance) {
   u32 var_i0, var_i2;
   f32 var_f1;
   var_i0 = 1u;
-  var_f1 = 2;
+  var_f1 = f32_reinterpret_i32(0x40000000);
   var_i2 = 0u;
   static_assert(sizeof(struct wasm_multi_if) <= 1024);
   CHECK_CALL_INDIRECT(instance->w2c_tab, w2c_test_i32_f32, var_i2);
@@ -855,7 +855,7 @@ void wasm_tailcall_w2c_test_tailcaller_0(void **instance_ptr, void *tail_call_st
   u32 var_i0, var_i2;
   f32 var_f1;
   var_i0 = 1u;
-  var_f1 = 2;
+  var_f1 = f32_reinterpret_i32(0x40000000);
   var_i2 = 0u;
   static_assert(sizeof(struct wasm_multi_if) <= 1024);
   CHECK_CALL_INDIRECT(instance->w2c_tab, w2c_test_i32_f32, var_i2);