cmd/compile: fix WriteFuncMap for new ABI.

replaced old type-based logic with new abi-based logic;
earlier versions of this CL compared them for equality.
For not-in-a-register, they match everywhere tested.

also modified GetFrameOffset to make it more like the one it replaces;
the LocalsOffset is subtracted.

Change-Id: I65ce7f0646c493c277df6b6f46e4839a0d886ac9
Reviewed-on: https://go-review.googlesource.com/c/go/+/302072
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/objw/objw.go b/src/cmd/compile/internal/objw/objw.go
index dfbcf51556..50ce7b747d 100644
--- a/src/cmd/compile/internal/objw/objw.go
+++ b/src/cmd/compile/internal/objw/objw.go
@@ -11,6 +11,8 @@ import (
 	"cmd/internal/obj"
 )
 
+// Uint8 writes an unsigned byte v into s at offset off,
+// and returns the next unused offset (i.e., off+1).
 func Uint8(s *obj.LSym, off int, v uint8) int {
 	return UintN(s, off, uint64(v), 1)
 }
@@ -27,6 +29,8 @@ func Uintptr(s *obj.LSym, off int, v uint64) int {
 	return UintN(s, off, v, types.PtrSize)
 }
 
+// UintN writes an unsigned integer v of size wid bytes into s at offset off,
+// and returns the next unused offset.
 func UintN(s *obj.LSym, off int, v uint64, wid int) int {
 	if off&(wid-1) != 0 {
 		base.Fatalf("duintxxLSym: misaligned: v=%d wid=%d off=%d", v, wid, off)
@@ -62,6 +66,8 @@ func Global(s *obj.LSym, width int32, flags int16) {
 	base.Ctxt.Globl(s, int64(width), int(flags))
 }
 
+// Bitvec writes the contents of bv into s as sequence of bytes
+// in little-endian order, and returns the next unused offset.
 func BitVec(s *obj.LSym, off int, bv bitvec.BitVec) int {
 	// Runtime reads the bitmaps as byte arrays. Oblige.
 	for j := 0; int32(j) < bv.N; j += 8 {