compiler.cfg.save-contexts: context-save-needed not needed because it's

the same as gc-map-insn

basis/compiler/cfg/save-contexts/save-contexts-docs.factor

@@ -5,21 +5,21 @@ IN: compiler.cfg.save-contexts
 HELP: insert-save-contexts
 { $values { "cfg" cfg } }
 { $description "Inserts " { $link ##save-context } " instructions in each " { $link basic-block } " in the cfg that needs them. Save contexts are needed after instructions that modify the context, or instructions that read parameter registers." }
-{ $see-also context-save-needed } ;
+{ $see-also insns-needs-save-context? } ;
 
 HELP: insns-needs-save-context?
 { $values { "insns" sequence } { "?" boolean } }
-{ $description "Whether to insert a " { $link ##save-context } " instruction in the given instruction sequence or not." }
-{ $see-also context-save-needed } ;
-
-HELP: context-save-needed
-{ $class-description "Union class of all instructions that needs to be preceeded by a " { $link ##save-context } " instruction. Only instructions that can allocate memory mandates save contexts." } ;
+{ $description "Whether to insert a " { $link ##save-context } " instruction in the given instruction sequence or not. Only instructions that can allocate memory mandates save contexts." }
+{ $see-also gc-map-insn } ;
 
 HELP: save-context-offset
 { $values { "insns" sequence } { "n" integer } }
 { $description { $link ##save-context } " must be placed after instructions that modify the context, or instructions that read parameter registers." } ;
 
 ARTICLE: "compiler.cfg.save-contexts" "Insert context saves"
-"Inserts " { $link ##save-context } " in blocks that need them." ;
+"Inserts " { $link ##save-context } " in blocks that need them."
+$nl
+"Main word:"
+{ $subsections insert-save-contexts } ;
 
 ABOUT: "compiler.cfg.save-contexts"

basis/compiler/cfg/save-contexts/save-contexts-tests.factor

@@ -4,6 +4,17 @@ compiler.cfg.save-contexts kernel namespaces tools.test
 cpu.x86.assembler.operands cpu.architecture ;
 IN: compiler.cfg.save-contexts.tests
 
+! insns-needs-save-context?
+{ t f } [
+    {
+        T{ ##call-gc }
+    } insns-needs-save-context?
+    {
+        T{ ##add f 1 2 3 }
+        T{ ##branch }
+    } insns-needs-save-context?
+] unit-test
+
 H{ } clone representations set
 
 V{

basis/compiler/cfg/save-contexts/save-contexts.factor

@@ -5,13 +5,12 @@ cpu.architecture kernel sequences ;
 IN: compiler.cfg.save-contexts
 
 UNION: context-modifier ##phi ##inc ##callback-inputs ;
-UNION: context-save-needed gc-map-insn ;
 
 : save-context-offset ( insns -- n )
     [ context-modifier? not ] find drop ;
 
 : insns-needs-save-context? ( insns -- ? )
-    [ context-save-needed? ] any? ;
+    [ gc-map-insn? ] any? ;
 
 : insert-save-context ( insns -- insns' )
     dup insns-needs-save-context? [