make -freg-struct-return visibly a negative alias of -fpcc-struct-return

The fact that both options accept negative forms suggests that maybe
they aren't negative forms of each other.  They are, but that isn't
clear even by examining common.opt.  Use NegativeAlias to make it
abundantly clear.

The 'Optimization' keyword next to freg-struct-return was the only
thing that caused flag_pcc_struct_return to be a per-function flag,
and ipa-inline relied on that.  After making it an alias, the
Optimization keyword was no longer operational.  I'm not sure it was
sensible or desirable for flag_pcc_struct_return to be a per-function
setting, but this patch does not intend to change behavior.

for  gcc/ChangeLog

	* common.opt (freg-struct-return): Make it explicitly
	fpcc-struct-return's NegativeAlias.  Copy Optimization...
	(freg-struct-return): ... here.

diff --git a/gcc/common.opt b/gcc/common.opt
index 40cab3cb36a33b147b881592919f0ed488fcd4dd..40d90817b8681790d54aac0a4c86cdf6a8f88b79 100644 (file)
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2412,7 +2412,7 @@ Common RejectNegative Joined UInteger Optimization
 -fpack-struct=<number> Set initial maximum structure member alignment.
 
 fpcc-struct-return
-Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
+Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN) Optimization
 Return small aggregates in memory, not registers.
 
 fpeel-loops
@@ -2602,7 +2602,7 @@ Common Var(flag_record_gcc_switches)
 Record gcc command line switches in the object file.
 
 freg-struct-return
-Common Var(flag_pcc_struct_return,0) Optimization
+Common NegativeAlias Alias(fpcc_struct_return) Optimization
 Return small aggregates in registers.
 
 fregmove