| Message ID | 217ce49a-cc7e-c142-6ae5-d580c486d771@foss.arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | Correct comment for ADDR_EXPR tree code. | expand |
On 03/23/2018 09:44 AM, Renlin Li wrote: > Hi all, > > This is a simple patch to correct the comment for ADDR_EXPR tree code. > > The resulting expression of ADDR_EXPR is a tree with POINTER_TYPE. > So the result mode should ptr_mode instead of Pmode. > > As far as I understand, Pmode is the addressing mode. But not the mode > to represent a pointer (or address?). > > Okay to commit? > > Regards, > Renlin > > gcc/ChangeLog: > > 2018-03-23 Renlin Li <renlin.li@arm.com> > > * tree.def (ADDR_EXPR): Correct the commnet.I'm not sure this is strictly correct. More importantly, I'm not sure why we care :-0 Modes are more of a target/RTL issue. Why a tree node needs to specify a mode in this case vs a type seems to be the more important question. jeff
Hi Jeff, On 23/03/18 23:19, Jeff Law wrote: > On 03/23/2018 09:44 AM, Renlin Li wrote: >> Hi all, >> >> This is a simple patch to correct the comment for ADDR_EXPR tree code. >> >> The resulting expression of ADDR_EXPR is a tree with POINTER_TYPE. >> So the result mode should ptr_mode instead of Pmode. >> >> As far as I understand, Pmode is the addressing mode. But not the mode >> to represent a pointer (or address?). >> >> Okay to commit? >> >> Regards, >> Renlin >> >> gcc/ChangeLog: >> >> 2018-03-23 Renlin Li <renlin.li@arm.com> >> >> * tree.def (ADDR_EXPR): Correct the commnet.I'm not sure this is strictly correct. More importantly, I'm not sure > why we care :-0 > > Modes are more of a target/RTL issue. Why a tree node needs to specify > a mode in this case vs a type seems to be the more important question. It is a very minor issue, I just come cross the comment which doesn't seem very right. I agree, the type is more meaningful than the machine mode to describe a tree node. The result of ADDR_EXPR should be an expression of POINTER_TYPE or REFERENCE_TYPE as the document indicates. I can replace the sentence "Result mode is Pmode." with "The result expression will always have pointer or reference type." Thanks! Renlin > > jeff > > >
diff --git a/gcc/tree.def b/gcc/tree.def index 31de6c0994de43c175b924d4ba578a131fb4d524..1e5aca811f801c54be9215a9d86028f50a4ec608 100644 --- a/gcc/tree.def +++ b/gcc/tree.def @@ -870,7 +870,7 @@ DEFTREECODE (COMPOUND_LITERAL_EXPR, "compound_literal_expr", tcc_expression, 1) DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1) /* & in C. Value is the address at which the operand's value resides. - Operand may have any mode. Result mode is Pmode. */ + Operand may have any mode. Result mode is ptr_mode. */ DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1) /* Operand0 is a function constant; result is part N of a function