Hi Roger,
Looks good. Please proceed with your commit.
Thank you,
Claudiu
-----Original Message-----
From: Roger Sayle <ro...@nextmovesoftware.com>
Sent: Friday, November 3, 2023 9:43 PM
To: gcc-patches@gcc.gnu.org
Cc: 'Claudiu Zissulescu' <claz...@gmail.com>
Subject: [ARC PATCH] Provide a TARGET_FOLD_BUILTIN target hook.
This patch implements a arc_fold_builtin target hook to allow ARC builtins to
be folded at the tree-level. Currently this function converts
__builtin_arc_swap into a LROTATE_EXPR at the tree-level, and evaluates
__builtin_arc_norm and __builtin_arc_normw of integer constant arguments at
compile-time. Because ARC_BUILTIIN_SWAP is now handled at the tree-level,
UNSPEC_ARC_SWAP no longer used, allowing it and the "swap" define_insn to be
removed.
An example benefit of folding things at compile-time is that calling
__builtin_arc_swap on the result of __builtin_arc_swap now eliminates both and
generates no code, and likewise calling __builtin_arc_swap of a constant
integer argument is evaluated at compile-time.
Tested with a cross-compiler to arc-linux hosted on x86_64, with no new
(compile-only) regressions from make -k check.
Ok for mainline if this passes Claudiu's nightly testing?
2023-11-03 Roger Sayle <ro...@nextmovesoftware.com>
gcc/ChangeLog
* config/arc/arc.cc (TARGET_FOLD_BUILTIN): Define to
arc_fold_builtin.
(arc_fold_builtin): New function. Convert ARC_BUILTIN_SWAP
into a rotate. Evaluate ARC_BUILTIN_NORM and
ARC_BUILTIN_NORMW of constant arguments.
* config/arc/arc.md (UNSPEC_ARC_SWAP): Delete.
(normw): Make output template/assembler whitespace consistent.
(swap): Remove define_insn, only use of SWAP UNSPEC.
* config/arc/builtins.def: Tweak indentation.
(SWAP): Expand using rotlsi2_cnt16 instead of using swap.
gcc/testsuite/ChangeLog
* gcc.target/arc/builtin_norm-1.c: New test case.
* gcc.target/arc/builtin_norm-2.c: Likewise.
* gcc.target/arc/builtin_normw-1.c: Likewise.
* gcc.target/arc/builtin_normw-2.c: Likewise.
* gcc.target/arc/builtin_swap-1.c: Likewise.
* gcc.target/arc/builtin_swap-2.c: Likewise.
* gcc.target/arc/builtin_swap-3.c: Likewise.
Thanks in advance,
Roger
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