Recent versions of GCC #10
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Why do you think it's the branch that you need?
Yes. Use the mainline ct-ng and custom newlib. Or, if you prefer doing everything yourself, use the mainline gcc and the same newlib.
Then you need to know what the xtensa configuration overlay is and how to apply it. |
jcmvbkbc
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Jun 11, 2022
A previous change in "Make debug printouts more robust" accidentally
removed double quotes around identifiers in debug printouts. This patch
restores those. So for example, we have:
Prev_Entity = Node #10 N_Defining_Identifier "foo" (Entity_Id=795)
and not:
Prev_Entity = Node #10 N_Defining_Identifier foo (Entity_Id=795)
This affects the output of -gnatdt, and certain calls normally done from
gdb.
gcc/ada/
* namet.ads, namet.adb (Write_Name_For_Debug): Add Quote
parameter to allow conditional addition of quotes. Note that
some calls to Write_Name_For_Debug, for example for file names,
shouldn't have quotes, as in some_package.adb:123:45.
* treepr.adb (Print_Name): Add double quotes around the name
using the above Quote parameters.
jcmvbkbc
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May 8, 2023
This patch fixes PR rtl-optimization/109476, which is a code quality
regression affecting AVR. The cause is that the lower-subreg pass is
sometimes overly aggressive, lowering the LSHIFTRT below:
(insn 7 4 8 2 (set (reg:HI 51)
(lshiftrt:HI (reg/v:HI 49 [ b ])
(const_int 8 [0x8]))) "t.ii":4:36 557 {lshrhi3}
(nil))
into a pair of QImode SUBREG assignments:
(insn 19 4 20 2 (set (subreg:QI (reg:HI 51) 0)
(reg:QI 54 [ b+1 ])) "t.ii":4:36 86 {movqi_insn_split}
(nil))
(insn 20 19 8 2 (set (subreg:QI (reg:HI 51) 1)
(const_int 0 [0])) "t.ii":4:36 86 {movqi_insn_split}
(nil))
but this idiom, SETs of SUBREGs, interferes with combine's ability
to associate/fuse instructions. The solution, on targets that
have a suitable ZERO_EXTEND (i.e. where the lower-subreg pass
wouldn't itself split a ZERO_EXTEND, so "splitting_zext" is false),
is to split/lower LSHIFTRT to a ZERO_EXTEND.
To answer Richard's question in comment #10 of the bugzilla PR,
the function resolve_shift_zext is called with one of four RTX
codes, ASHIFTRT, LSHIFTRT, ZERO_EXTEND and ASHIFT, but only with
LSHIFTRT can the setting of low_part and high_part SUBREGs be
replaced by a ZERO_EXTEND. For ASHIFTRT, we require a sign
extension, so don't set the high_part to zero; if we're splitting
a ZERO_EXTEND then it doesn't make sense to replace it with a
ZERO_EXTEND, and for ASHIFT we've played games to swap the
high_part and low_part SUBREGs, so that we assign the low_part
to zero (for double word shifts by greater than word size bits).
2023-04-28 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
PR rtl-optimization/109476
* lower-subreg.cc: Include explow.h for force_reg.
(find_decomposable_shift_zext): Pass an additional SPEED_P argument.
If decomposing a suitable LSHIFTRT and we're not splitting
ZERO_EXTEND (based on the current SPEED_P), then use a ZERO_EXTEND
instead of setting a high part SUBREG to zero, which helps combine.
(decompose_multiword_subregs): Update call to resolve_shift_zext.
gcc/testsuite/ChangeLog
PR rtl-optimization/109476
* gcc.target/avr/mmcu/pr109476.c: New test case.
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Hello,
I've been spending the last several hours, trying to get the "xtensa-ctng-7.2.0" branch to work. I've been able to build the toolchain, however the only binaries I could get was big endian no matter how I compiled. I'm starting to think that branch isn't really ready to be used.
Is there a way to get a recent version of GCC (>=6) working with little endian lx106 binaries? Specifically for ESP8266 mcus.
I'm not using ct-ng and manually compiling everything. I may be using some incorrect versions of other stuff.
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