cmd/link,runtime: remove unused fields from inlinedCall

The parent, file, and line fields are no longer used now that we have
parentPc to find the parent and NOPs in the parent to attach file/line
pcdata to.

Removing these fields reduces the binary size of cmd/go on linux-amd64
by 1.1%.

Fixes #54849.

Change-Id: If58f08622736b2b322288608776f8bedf0c3fd17
Reviewed-on: https://go-review.googlesource.com/c/go/+/427960
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/cmd/link/internal/ld/pcln.go b/src/cmd/link/internal/ld/pcln.go
index 45a4e07fb74a1c57c5aaed50acabddf8355da503..9b743a853050c453c31138f77be5123fc1eedabb 100644 (file)
--- a/src/cmd/link/internal/ld/pcln.go
+++ b/src/cmd/link/internal/ld/pcln.go
@@ -162,26 +162,22 @@ func genInlTreeSym(ctxt *Link, cu *sym.CompilationUnit, fi loader.FuncInfo, arch
        ninl := fi.NumInlTree()
        for i := 0; i < int(ninl); i++ {
                call := fi.InlTree(i)
-               val := call.File
                nameoff, ok := nameOffsets[call.Func]
                if !ok {
                        panic("couldn't find function name offset")
                }
 
-               inlTreeSym.SetUint16(arch, int64(i*20+0), uint16(call.Parent))
                inlFunc := ldr.FuncInfo(call.Func)
-
                var funcID objabi.FuncID
                if inlFunc.Valid() {
                        funcID = inlFunc.FuncID()
                }
-               inlTreeSym.SetUint8(arch, int64(i*20+2), uint8(funcID))
-
-               // byte 3 is unused
-               inlTreeSym.SetUint32(arch, int64(i*20+4), uint32(val))
-               inlTreeSym.SetUint32(arch, int64(i*20+8), uint32(call.Line))
-               inlTreeSym.SetUint32(arch, int64(i*20+12), uint32(nameoff))
-               inlTreeSym.SetUint32(arch, int64(i*20+16), uint32(call.ParentPC))
+               // Construct runtime.inlinedCall value.
+               const size = 12
+               inlTreeSym.SetUint8(arch, int64(i*size+0), uint8(funcID))
+               // Bytes 1-3 are unused.
+               inlTreeSym.SetUint32(arch, int64(i*size+4), uint32(nameoff))
+               inlTreeSym.SetUint32(arch, int64(i*size+8), uint32(call.ParentPC))
        }
        return its
 }

diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index 69190233a27cb0d77d813b50ded71b0eed3a5add..a1a7eba83ceb79e5d5bccccb0064818267c770de 100644 (file)
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -117,8 +117,7 @@ func (ci *Frames) Next() (frame Frame, more bool) {
                                // Note: entry is not modified. It always refers to a real frame, not an inlined one.
                                f = nil
                                name = funcnameFromNameoff(funcInfo, inltree[ix].func_)
-                               // File/line is already correct.
-                               // TODO: remove file/line from InlinedCall?
+                               // File/line from funcline1 below are already correct.
                        }
                }
                ci.frames = append(ci.frames, Frame{
@@ -1173,11 +1172,8 @@ func stackmapdata(stkmap *stackmap, n int32) bitvector {
 
 // inlinedCall is the encoding of entries in the FUNCDATA_InlTree table.
 type inlinedCall struct {
-       parent   int16  // index of parent in the inltree, or < 0
        funcID   funcID // type of the called function
-       _        byte
-       file     int32 // perCU file index for inlined call. See cmd/link:pcln.go
-       line     int32 // line number of the call site
+       _        [3]byte
        func_    int32 // offset into pclntab for name of called function
        parentPc int32 // position of an instruction whose source position is the call site (offset from entry)
 }