| commit | 0b478cddf9e95406cd865c94bf99705ec8acddde | |
| author | Richard Earnshaw <rearnsha@arm.com> | |
| Fri, 18 Oct 2019 19:03:19 +0000 (18 19:03 +0000) | ||
| committer | Richard Earnshaw <rearnsha@gcc.gnu.org> | |
| Fri, 18 Oct 2019 19:03:19 +0000 (18 19:03 +0000) | ||
| tree | e4aea46ee82842c8dc421bca46b1c22e20ade936 | treesnapshot (tar.gz zip) |
| parent | f6ff841bc8dd87ce364deb217dc6d1ec5dc31de8 | commitdiff |
[arm] Add alternative canonicalizations for subtract-with-carry + shift
This patch adds a couple of alternative canonicalizations to allow
combine to match a subtract-with-carry operation when one of the operands
is shifted first. The most common case of this is when combining a
sign-extend of one operand with a long-long value during subtraction.
The RSC variant is only enabled for Arm, the SBC variant for any 32-bit
compilation.
* config/arm/arm.md (subsi3_carryin_shift_alt): New pattern.
(rsbsi3_carryin_shift_alt): Likewise.
From-SVN: r277176
This patch adds a couple of alternative canonicalizations to allow
combine to match a subtract-with-carry operation when one of the operands
is shifted first. The most common case of this is when combining a
sign-extend of one operand with a long-long value during subtraction.
The RSC variant is only enabled for Arm, the SBC variant for any 32-bit
compilation.
* config/arm/arm.md (subsi3_carryin_shift_alt): New pattern.
(rsbsi3_carryin_shift_alt): Likewise.
From-SVN: r277176
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