cmd/cc, cmd/gc: stop generating 'argsize' PCDATA

The argsize PCDATA was specifying the number of
bytes passed to a function call, so that if the function
did not specify its argument count, the garbage collector
could use the call site information to scan those bytes
conservatively. We don't do that anymore, so stop
generating the information.

LGTM=khr
R=khr
CC=golang-codereviews
https://codereview.appspot.com/139530043

12 files changed, 0 insertions, 97 deletions

diff --git a/src/cmd/5c/cgen.c b/src/cmd/5c/cgen.c
index 9be10bf45..5a049ae62 100644
--- a/src/cmd/5c/cgen.c
+++ b/src/cmd/5c/cgen.c
@@ -366,14 +366,12 @@ _cgen(Node *n, Node *nn, int inrel)
 		if(REGARG >= 0)
 			o = reg[REGARG];
 		gargs(r, &nod, &nod1);
-		gpcdata(PCDATA_ArgSize, curarg);
 		if(l->addable < INDEXED) {
 			reglcgen(&nod, l, Z);
 			gopcode(OFUNC, Z, Z, &nod);
 			regfree(&nod);
 		} else
 			gopcode(OFUNC, Z, Z, l);
-		gpcdata(PCDATA_ArgSize, -1);
 		if(REGARG >= 0)
 			if(o != reg[REGARG])
 				reg[REGARG]--;
diff --git a/src/cmd/5g/gg.h b/src/cmd/5g/gg.h
index 62f73c865..00914bfa3 100644
--- a/src/cmd/5g/gg.h
+++ b/src/cmd/5g/gg.h
@@ -109,7 +109,6 @@ void	split64(Node*, Node*, Node*);
 void	splitclean(void);
 Node*	ncon(uint32 i);
 void	gtrack(Sym*);
-void	gargsize(int32);
 
 /*
  * obj.c
diff --git a/src/cmd/5g/ggen.c b/src/cmd/5g/ggen.c
index 6174e760c..53cddb760 100644
--- a/src/cmd/5g/ggen.c
+++ b/src/cmd/5g/ggen.c
@@ -179,28 +179,12 @@ fixautoused(Prog* p)
 void
 ginscall(Node *f, int proc)
 {
-	int32 arg;
 	Prog *p;
 	Node n1, r, r1, con;
 
 	if(f->type != T)
 		setmaxarg(f->type);
 
-	arg = -1;
-	// Most functions have a fixed-size argument block, so traceback uses that during unwind.
-	// Not all, though: there are some variadic functions in package runtime,
-	// and for those we emit call-specific metadata recorded by caller.
-	// Reflect generates functions with variable argsize (see reflect.methodValueCall/makeFuncStub),
-	// so we do this for all indirect calls as well.
-	if(f->type != T && (f->sym == S || (f->sym != S && f->sym->pkg == runtimepkg) || proc == 1 || proc == 2)) {
-		arg = f->type->argwid;
-		if(proc == 1 || proc == 2)
-			arg += 3*widthptr;
-	}
-
-	if(arg != -1)
-		gargsize(arg);
-
 	switch(proc) {
 	default:
 		fatal("ginscall: bad proc %d", proc);
@@ -297,9 +281,6 @@ ginscall(Node *f, int proc)
 		}
 		break;
 	}
-	
-	if(arg != -1)
-		gargsize(-1);
 }
 
 /*
diff --git a/src/cmd/5g/gsubr.c b/src/cmd/5g/gsubr.c
index ebd2c70a0..93bfafef6 100644
--- a/src/cmd/5g/gsubr.c
+++ b/src/cmd/5g/gsubr.c
@@ -206,16 +206,6 @@ ggloblnod(Node *nam)
 }
 
 void
-gargsize(int32 size)
-{
-	Node n1, n2;
-	
-	nodconst(&n1, types[TINT32], PCDATA_ArgSize);
-	nodconst(&n2, types[TINT32], size);
-	gins(APCDATA, &n1, &n2);
-}
-
-void
 ggloblsym(Sym *s, int32 width, int8 flags)
 {
 	Prog *p;
diff --git a/src/cmd/6c/cgen.c b/src/cmd/6c/cgen.c
index bb09ec05d..68dd7bb5f 100644
--- a/src/cmd/6c/cgen.c
+++ b/src/cmd/6c/cgen.c
@@ -945,7 +945,6 @@ cgen(Node *n, Node *nn)
 			return;
 		}
 		gargs(r, &nod, &nod1);
-		gpcdata(PCDATA_ArgSize, curarg);
 		if(l->addable < INDEXED) {
 			reglcgen(&nod, l, nn);
 			nod.op = OREGISTER;
@@ -953,12 +952,9 @@ cgen(Node *n, Node *nn)
 			regfree(&nod);
 		} else
 			gopcode(OFUNC, n->type, Z, l);
-		gpcdata(PCDATA_ArgSize, -1);
 		if(REGARG >= 0 && reg[REGARG])
 			reg[REGARG]--;
 		regret(&nod, n, l->type, 1); // update maxarg if nothing else
-		gpcdata(PCDATA_ArgSize, curarg);
-		gpcdata(PCDATA_ArgSize, -1);
 		if(nn != Z)
 			gmove(&nod, nn);
 		if(nod.op == OREGISTER)
diff --git a/src/cmd/6g/gg.h b/src/cmd/6g/gg.h
index 27f6c01fe..fe69d5c96 100644
--- a/src/cmd/6g/gg.h
+++ b/src/cmd/6g/gg.h
@@ -99,7 +99,6 @@ int	sudoaddable(int, Node*, Addr*);
 void	afunclit(Addr*, Node*);
 void	nodfconst(Node*, Type*, Mpflt*);
 void	gtrack(Sym*);
-void	gargsize(vlong);
 void	fixlargeoffset(Node *n);
 
 /*
diff --git a/src/cmd/6g/ggen.c b/src/cmd/6g/ggen.c
index 5a9b8418c..987473cca 100644
--- a/src/cmd/6g/ggen.c
+++ b/src/cmd/6g/ggen.c
@@ -175,7 +175,6 @@ fixautoused(Prog *p)
 void
 ginscall(Node *f, int proc)
 {
-	int32 arg;
 	Prog *p;
 	Node reg, con;
 	Node r1;
@@ -183,21 +182,6 @@ ginscall(Node *f, int proc)
 	if(f->type != T)
 		setmaxarg(f->type);
 
-	arg = -1;
-	// Most functions have a fixed-size argument block, so traceback uses that during unwind.
-	// Not all, though: there are some variadic functions in package runtime,
-	// and for those we emit call-specific metadata recorded by caller.
-	// Reflect generates functions with variable argsize (see reflect.methodValueCall/makeFuncStub),
-	// so we do this for all indirect calls as well.
-	if(f->type != T && (f->sym == S || (f->sym != S && f->sym->pkg == runtimepkg) || proc == 1 || proc == 2)) {
-		arg = f->type->argwid;
-		if(proc == 1 || proc == 2)
-			arg += 2*widthptr;
-	}
-
-	if(arg != -1)
-		gargsize(arg);
-
 	switch(proc) {
 	default:
 		fatal("ginscall: bad proc %d", proc);
@@ -275,9 +259,6 @@ ginscall(Node *f, int proc)
 		}
 		break;
 	}
-
-	if(arg != -1)
-		gargsize(-1);
 }
 
 /*
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index e1ed3b3b8..5bd924660 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -215,16 +215,6 @@ gtrack(Sym *s)
 }
 
 void
-gargsize(vlong size)
-{
-	Node n1, n2;
-	
-	nodconst(&n1, types[TINT32], PCDATA_ArgSize);
-	nodconst(&n2, types[TINT32], size);
-	gins(APCDATA, &n1, &n2);
-}
-
-void
 ggloblsym(Sym *s, int32 width, int8 flags)
 {
 	Prog *p;
diff --git a/src/cmd/8c/cgen.c b/src/cmd/8c/cgen.c
index 6f0f7c97f..87e8fdad8 100644
--- a/src/cmd/8c/cgen.c
+++ b/src/cmd/8c/cgen.c
@@ -938,7 +938,6 @@ cgen(Node *n, Node *nn)
 			return;
 		}
 		gargs(r, &nod, &nod1);
-		gpcdata(PCDATA_ArgSize, curarg);
 		if(l->addable < INDEXED) {
 			reglcgen(&nod, l, nn);
 			nod.op = OREGISTER;
@@ -946,7 +945,6 @@ cgen(Node *n, Node *nn)
 			regfree(&nod);
 		} else
 			gopcode(OFUNC, n->type, Z, l);
-		gpcdata(PCDATA_ArgSize, -1);
 		if(REGARG >= 0 && reg[REGARG])
 			reg[REGARG]--;
 		regret(&nod, n, l->type, 1); // update maxarg if nothing else
diff --git a/src/cmd/8g/gg.h b/src/cmd/8g/gg.h
index bdefa93b5..238f92765 100644
--- a/src/cmd/8g/gg.h
+++ b/src/cmd/8g/gg.h
@@ -114,7 +114,6 @@ void	split64(Node*, Node*, Node*);
 void	splitclean(void);
 void	nswap(Node*, Node*);
 void	gtrack(Sym*);
-void	gargsize(int32);
 /*
  * cplx.c
  */
diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
index 6038731f7..a095be36e 100644
--- a/src/cmd/8g/ggen.c
+++ b/src/cmd/8g/ggen.c
@@ -217,21 +217,6 @@ ginscall(Node *f, int proc)
 	if(f->type != T)
 		setmaxarg(f->type);
 
-	arg = -1;
-	// Most functions have a fixed-size argument block, so traceback uses that during unwind.
-	// Not all, though: there are some variadic functions in package runtime,
-	// and for those we emit call-specific metadata recorded by caller.
-	// Reflect generates functions with variable argsize (see reflect.methodValueCall/makeFuncStub),
-	// so we do this for all indirect calls as well.
-	if(f->type != T && (f->sym == S || (f->sym != S && f->sym->pkg == runtimepkg) || proc == 1 || proc == 2)) {
-		arg = f->type->argwid;
-		if(proc == 1 || proc == 2)
-			arg += 2*widthptr;
-	}
-
-	if(arg != -1)
-		gargsize(arg);
-
 	switch(proc) {
 	default:
 		fatal("ginscall: bad proc %d", proc);
@@ -293,9 +278,6 @@ ginscall(Node *f, int proc)
 		}
 		break;
 	}
-	
-	if(arg != -1)
-		gargsize(-1);
 }
 
 /*
diff --git a/src/cmd/8g/gsubr.c b/src/cmd/8g/gsubr.c
index 9f923cc9a..a83d048f4 100644
--- a/src/cmd/8g/gsubr.c
+++ b/src/cmd/8g/gsubr.c
@@ -206,16 +206,6 @@ ggloblnod(Node *nam)
 }
 
 void
-gargsize(int32 size)
-{
-	Node n1, n2;
-	
-	nodconst(&n1, types[TINT32], PCDATA_ArgSize);
-	nodconst(&n2, types[TINT32], size);
-	gins(APCDATA, &n1, &n2);
-}
-
-void
 ggloblsym(Sym *s, int32 width, int8 flags)
 {
 	Prog *p;