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[Bug target/42498] GCC can't use smull to compute int * int --> long long
- From: "markusl dot se78 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 28 Dec 2009 17:59:06 -0000
- Subject: [Bug target/42498] GCC can't use smull to compute int * int --> long long
- References: <bug-42498-17659@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #1 from markusl dot se78 at gmail dot com 2009-12-28 17:59 -------
Another solution might be to have a define_insn_and_split for a 64x64->64bit
multiply allowing the combiner to do its job combining into a widening
multiplication and if this fails the insn will later be split into the double
word multiply sequence. Anyway this is what I had in mind for fixing the same
issue with a private port (based on gcc 4.4.1). Are there any obvious drawbacks
of such an approach (besides that it is local and needs to be applied for every
target that sees the problem)?
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markusl dot se78 at gmail dot com changed:
What |Removed |Added
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CC| |markusl dot se78 at gmail
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42498