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Summary: This is the first change to enable the TLI to be built per-function so that -fno-builtin* handling can be migrated to use function attributes. See discussion on D61634 for background. This is an enabler for fixing handling of these options for LTO, for example. This change should not affect behavior, as the provided function is not yet used to build a specifically per-function TLI, but rather enables that migration. Most of the changes were very mechanical, e.g. passing a Function to the legacy analysis pass's getTLI interface, or in Module level cases, adding a callback. This is similar to the way the per-function TTI analysis works. There was one place where we were looking for builtins but not in the context of a specific function. See FindCXAAtExit in lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround could provide the wrong behavior in some corner cases. Suggestions welcome. Reviewers: chandlerc, hfinkel Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66428 llvm-svn: 371284
Analysis Opportunities:
//===---------------------------------------------------------------------===//
In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the
ScalarEvolution expression for %r is this:
{1,+,3,+,2}<loop>
Outside the loop, this could be evaluated simply as (%n * %n), however
ScalarEvolution currently evaluates it as
(-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n))
In addition to being much more complicated, it involves i65 arithmetic,
which is very inefficient when expanded into code.
//===---------------------------------------------------------------------===//
In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll,
ScalarEvolution is forming this expression:
((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32)))
This could be folded to
(-1 * (trunc i64 undef to i32))
//===---------------------------------------------------------------------===//