Rename io_writer.write_fast_etc
diff --git a/internal/cgen/builtin.go b/internal/cgen/builtin.go
index 7f7bb64..197c7f3 100644
--- a/internal/cgen/builtin.go
+++ b/internal/cgen/builtin.go
@@ -870,25 +870,25 @@
 	t.IDPeekU64LE - peekMethodsBase:      {64, 64, 'l'},
 }
 
-const writeFastMethodsBase = t.IDWriteFastU8
+const writeFastMethodsBase = t.IDWriteU8Fast
 
 var writeFastMethods = [...]struct {
 	n          uint8
 	endianness uint8
 }{
-	t.IDWriteFastU8 - writeFastMethodsBase:    {8, 'b'},
-	t.IDWriteFastU16BE - writeFastMethodsBase: {16, 'b'},
-	t.IDWriteFastU16LE - writeFastMethodsBase: {16, 'l'},
-	t.IDWriteFastU24BE - writeFastMethodsBase: {24, 'b'},
-	t.IDWriteFastU24LE - writeFastMethodsBase: {24, 'l'},
-	t.IDWriteFastU32BE - writeFastMethodsBase: {32, 'b'},
-	t.IDWriteFastU32LE - writeFastMethodsBase: {32, 'l'},
-	t.IDWriteFastU40BE - writeFastMethodsBase: {40, 'b'},
-	t.IDWriteFastU40LE - writeFastMethodsBase: {40, 'l'},
-	t.IDWriteFastU48BE - writeFastMethodsBase: {48, 'b'},
-	t.IDWriteFastU48LE - writeFastMethodsBase: {48, 'l'},
-	t.IDWriteFastU56BE - writeFastMethodsBase: {56, 'b'},
-	t.IDWriteFastU56LE - writeFastMethodsBase: {56, 'l'},
-	t.IDWriteFastU64BE - writeFastMethodsBase: {64, 'b'},
-	t.IDWriteFastU64LE - writeFastMethodsBase: {64, 'l'},
+	t.IDWriteU8Fast - writeFastMethodsBase:    {8, 'b'},
+	t.IDWriteU16BEFast - writeFastMethodsBase: {16, 'b'},
+	t.IDWriteU16LEFast - writeFastMethodsBase: {16, 'l'},
+	t.IDWriteU24BEFast - writeFastMethodsBase: {24, 'b'},
+	t.IDWriteU24LEFast - writeFastMethodsBase: {24, 'l'},
+	t.IDWriteU32BEFast - writeFastMethodsBase: {32, 'b'},
+	t.IDWriteU32LEFast - writeFastMethodsBase: {32, 'l'},
+	t.IDWriteU40BEFast - writeFastMethodsBase: {40, 'b'},
+	t.IDWriteU40LEFast - writeFastMethodsBase: {40, 'l'},
+	t.IDWriteU48BEFast - writeFastMethodsBase: {48, 'b'},
+	t.IDWriteU48LEFast - writeFastMethodsBase: {48, 'l'},
+	t.IDWriteU56BEFast - writeFastMethodsBase: {56, 'b'},
+	t.IDWriteU56LEFast - writeFastMethodsBase: {56, 'l'},
+	t.IDWriteU64BEFast - writeFastMethodsBase: {64, 'b'},
+	t.IDWriteU64LEFast - writeFastMethodsBase: {64, 'l'},
 }
diff --git a/lang/builtin/builtin.go b/lang/builtin/builtin.go
index 98c55f0..38b96d8 100644
--- a/lang/builtin/builtin.go
+++ b/lang/builtin/builtin.go
@@ -292,23 +292,23 @@
 	// TODO: these should have an explicit pre-condition "available() >= N".
 	// For now, that's implicitly checked (i.e. hard coded).
 	//
-	// The io_writer has write_fast_etc methods, not poke_etc and skip_fast,
+	// The io_writer has write_etc_fast methods, not poke_etc and skip_fast,
 	// because skip_fast could leave uninitialized bytes in the io_buffer.
-	"io_writer.write_fast_u8!(a: u8)",
-	"io_writer.write_fast_u16be!(a: u16)",
-	"io_writer.write_fast_u16le!(a: u16)",
-	"io_writer.write_fast_u24be!(a: u32[..= 0xFFFFFF])",
-	"io_writer.write_fast_u24le!(a: u32[..= 0xFFFFFF])",
-	"io_writer.write_fast_u32be!(a: u32)",
-	"io_writer.write_fast_u32le!(a: u32)",
-	"io_writer.write_fast_u40be!(a: u64[..= 0xFFFFFFFFFF])",
-	"io_writer.write_fast_u40le!(a: u64[..= 0xFFFFFFFFFF])",
-	"io_writer.write_fast_u48be!(a: u64[..= 0xFFFFFFFFFFFF])",
-	"io_writer.write_fast_u48le!(a: u64[..= 0xFFFFFFFFFFFF])",
-	"io_writer.write_fast_u56be!(a: u64[..= 0xFFFFFFFFFFFFFF])",
-	"io_writer.write_fast_u56le!(a: u64[..= 0xFFFFFFFFFFFFFF])",
-	"io_writer.write_fast_u64be!(a: u64)",
-	"io_writer.write_fast_u64le!(a: u64)",
+	"io_writer.write_u8_fast!(a: u8)",
+	"io_writer.write_u16be_fast!(a: u16)",
+	"io_writer.write_u16le_fast!(a: u16)",
+	"io_writer.write_u24be_fast!(a: u32[..= 0xFFFFFF])",
+	"io_writer.write_u24le_fast!(a: u32[..= 0xFFFFFF])",
+	"io_writer.write_u32be_fast!(a: u32)",
+	"io_writer.write_u32le_fast!(a: u32)",
+	"io_writer.write_u40be_fast!(a: u64[..= 0xFFFFFFFFFF])",
+	"io_writer.write_u40le_fast!(a: u64[..= 0xFFFFFFFFFF])",
+	"io_writer.write_u48be_fast!(a: u64[..= 0xFFFFFFFFFFFF])",
+	"io_writer.write_u48le_fast!(a: u64[..= 0xFFFFFFFFFFFF])",
+	"io_writer.write_u56be_fast!(a: u64[..= 0xFFFFFFFFFFFFFF])",
+	"io_writer.write_u56le_fast!(a: u64[..= 0xFFFFFFFFFFFFFF])",
+	"io_writer.write_u64be_fast!(a: u64)",
+	"io_writer.write_u64le_fast!(a: u64)",
 
 	"io_writer.available() u64",
 	"io_writer.count_since(mark: u64) u64",
diff --git a/lang/check/bounds.go b/lang/check/bounds.go
index 2fe46da..16450ea 100644
--- a/lang/check/bounds.go
+++ b/lang/check/bounds.go
@@ -1263,21 +1263,21 @@
 	t.IDPeekU64BE - t.IDPeekU8:      {eight, false},
 	t.IDPeekU64LE - t.IDPeekU8:      {eight, false},
 
-	t.IDWriteFastU8 - t.IDPeekU8:    {one, true},
-	t.IDWriteFastU16BE - t.IDPeekU8: {two, true},
-	t.IDWriteFastU16LE - t.IDPeekU8: {two, true},
-	t.IDWriteFastU24BE - t.IDPeekU8: {three, true},
-	t.IDWriteFastU24LE - t.IDPeekU8: {three, true},
-	t.IDWriteFastU32BE - t.IDPeekU8: {four, true},
-	t.IDWriteFastU32LE - t.IDPeekU8: {four, true},
-	t.IDWriteFastU40BE - t.IDPeekU8: {five, true},
-	t.IDWriteFastU40LE - t.IDPeekU8: {five, true},
-	t.IDWriteFastU48BE - t.IDPeekU8: {six, true},
-	t.IDWriteFastU48LE - t.IDPeekU8: {six, true},
-	t.IDWriteFastU56BE - t.IDPeekU8: {seven, true},
-	t.IDWriteFastU56LE - t.IDPeekU8: {seven, true},
-	t.IDWriteFastU64BE - t.IDPeekU8: {eight, true},
-	t.IDWriteFastU64LE - t.IDPeekU8: {eight, true},
+	t.IDWriteU8Fast - t.IDPeekU8:    {one, true},
+	t.IDWriteU16BEFast - t.IDPeekU8: {two, true},
+	t.IDWriteU16LEFast - t.IDPeekU8: {two, true},
+	t.IDWriteU24BEFast - t.IDPeekU8: {three, true},
+	t.IDWriteU24LEFast - t.IDPeekU8: {three, true},
+	t.IDWriteU32BEFast - t.IDPeekU8: {four, true},
+	t.IDWriteU32LEFast - t.IDPeekU8: {four, true},
+	t.IDWriteU40BEFast - t.IDPeekU8: {five, true},
+	t.IDWriteU40LEFast - t.IDPeekU8: {five, true},
+	t.IDWriteU48BEFast - t.IDPeekU8: {six, true},
+	t.IDWriteU48LEFast - t.IDPeekU8: {six, true},
+	t.IDWriteU56BEFast - t.IDPeekU8: {seven, true},
+	t.IDWriteU56LEFast - t.IDPeekU8: {seven, true},
+	t.IDWriteU64BEFast - t.IDPeekU8: {eight, true},
+	t.IDWriteU64LEFast - t.IDPeekU8: {eight, true},
 
 	t.IDWriteSimpleTokenFast - t.IDPeekU8: {one, true},
 }
diff --git a/lang/token/list.go b/lang/token/list.go
index 73130c0..839b582 100644
--- a/lang/token/list.go
+++ b/lang/token/list.go
@@ -608,21 +608,21 @@
 
 	// --------
 
-	IDWriteFastU8    = ID(0x1E1)
-	IDWriteFastU16BE = ID(0x1E2)
-	IDWriteFastU16LE = ID(0x1E3)
-	IDWriteFastU24BE = ID(0x1E4)
-	IDWriteFastU24LE = ID(0x1E5)
-	IDWriteFastU32BE = ID(0x1E6)
-	IDWriteFastU32LE = ID(0x1E7)
-	IDWriteFastU40BE = ID(0x1E8)
-	IDWriteFastU40LE = ID(0x1E9)
-	IDWriteFastU48BE = ID(0x1EA)
-	IDWriteFastU48LE = ID(0x1EB)
-	IDWriteFastU56BE = ID(0x1EC)
-	IDWriteFastU56LE = ID(0x1ED)
-	IDWriteFastU64BE = ID(0x1EE)
-	IDWriteFastU64LE = ID(0x1EF)
+	IDWriteU8Fast    = ID(0x1E1)
+	IDWriteU16BEFast = ID(0x1E2)
+	IDWriteU16LEFast = ID(0x1E3)
+	IDWriteU24BEFast = ID(0x1E4)
+	IDWriteU24LEFast = ID(0x1E5)
+	IDWriteU32BEFast = ID(0x1E6)
+	IDWriteU32LEFast = ID(0x1E7)
+	IDWriteU40BEFast = ID(0x1E8)
+	IDWriteU40LEFast = ID(0x1E9)
+	IDWriteU48BEFast = ID(0x1EA)
+	IDWriteU48LEFast = ID(0x1EB)
+	IDWriteU56BEFast = ID(0x1EC)
+	IDWriteU56LEFast = ID(0x1ED)
+	IDWriteU64BEFast = ID(0x1EE)
+	IDWriteU64LEFast = ID(0x1EF)
 
 	// --------
 
@@ -963,21 +963,21 @@
 
 	// --------
 
-	IDWriteFastU8:    "write_fast_u8",
-	IDWriteFastU16BE: "write_fast_u16be",
-	IDWriteFastU16LE: "write_fast_u16le",
-	IDWriteFastU24BE: "write_fast_u24be",
-	IDWriteFastU24LE: "write_fast_u24le",
-	IDWriteFastU32BE: "write_fast_u32be",
-	IDWriteFastU32LE: "write_fast_u32le",
-	IDWriteFastU40BE: "write_fast_u40be",
-	IDWriteFastU40LE: "write_fast_u40le",
-	IDWriteFastU48BE: "write_fast_u48be",
-	IDWriteFastU48LE: "write_fast_u48le",
-	IDWriteFastU56BE: "write_fast_u56be",
-	IDWriteFastU56LE: "write_fast_u56le",
-	IDWriteFastU64BE: "write_fast_u64be",
-	IDWriteFastU64LE: "write_fast_u64le",
+	IDWriteU8Fast:    "write_u8_fast",
+	IDWriteU16BEFast: "write_u16be_fast",
+	IDWriteU16LEFast: "write_u16le_fast",
+	IDWriteU24BEFast: "write_u24be_fast",
+	IDWriteU24LEFast: "write_u24le_fast",
+	IDWriteU32BEFast: "write_u32be_fast",
+	IDWriteU32LEFast: "write_u32le_fast",
+	IDWriteU40BEFast: "write_u40be_fast",
+	IDWriteU40LEFast: "write_u40le_fast",
+	IDWriteU48BEFast: "write_u48be_fast",
+	IDWriteU48LEFast: "write_u48le_fast",
+	IDWriteU56BEFast: "write_u56be_fast",
+	IDWriteU56LEFast: "write_u56le_fast",
+	IDWriteU64BEFast: "write_u64be_fast",
+	IDWriteU64LEFast: "write_u64le_fast",
 
 	// --------
 
diff --git a/std/deflate/decode_huffman_fast.wuffs b/std/deflate/decode_huffman_fast.wuffs
index c9f7e0a..54666b8 100644
--- a/std/deflate/decode_huffman_fast.wuffs
+++ b/std/deflate/decode_huffman_fast.wuffs
@@ -98,7 +98,7 @@
 
 		if (table_entry >> 31) <> 0 {
 			// Literal.
-			args.dst.write_fast_u8!(a: ((table_entry >> 8) & 0xFF) as base.u8)
+			args.dst.write_u8_fast!(a: ((table_entry >> 8) & 0xFF) as base.u8)
 			continue.loop
 		} else if (table_entry >> 30) <> 0 {
 			// No-op; code continues past the if-else chain.
@@ -136,7 +136,7 @@
 
 			if (table_entry >> 31) <> 0 {
 				// Literal.
-				args.dst.write_fast_u8!(a: ((table_entry >> 8) & 0xFF) as base.u8)
+				args.dst.write_u8_fast!(a: ((table_entry >> 8) & 0xFF) as base.u8)
 				continue.loop
 			} else if (table_entry >> 30) <> 0 {
 				// No-op; code continues past the if-else chain.