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93798daa3e
This allows us to simplify this:
union vec2d {
double e[2];
double v __attribute__((vector_size(16)));
};
typedef union vec2d vec2d;
static vec2d a={{1,2}}, b={{3,4}};
vec2d foo () {
return (vec2d){ .v = a.v + b.v * (vec2d){{5,5}}.v };
}
down to:
define %0 @foo() nounwind ssp {
entry:
%mrv5 = insertvalue %0 undef, double 1.600000e+01, 0 ; <%0> [#uses=1]
%mrv6 = insertvalue %0 %mrv5, double 2.200000e+01, 1 ; <%0> [#uses=1]
ret %0 %mrv6
}
instead of:
define %0 @foo() nounwind ssp {
entry:
%mrv5 = insertvalue %0 undef, double extractelement (<2 x double> fadd (<2 x double> fmul (<2 x double> bitcast (<1 x i128> <i128 85174437667405312423031577302488055808> to <2 x double>), <2 x double> <double 3.000000e+00, double 4.000000e+00>), <2 x double> <double 1.000000e+00, double 2.000000e+00>), i32 0), 0 ; <%0> [#uses=1]
%mrv6 = insertvalue %0 %mrv5, double extractelement (<2 x double> fadd (<2 x double> fmul (<2 x double> bitcast (<1 x i128> <i128 85174437667405312423031577302488055808> to <2 x double>), <2 x double> <double 3.000000e+00, double 4.000000e+00>), <2 x double> <double 1.000000e+00, double 2.000000e+00>), i32 1), 1 ; <%0> [#uses=1]
ret %0 %mrv6
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85040 91177308-0d34-0410-b5e6-96231b3b80d8
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.
//===---------------------------------------------------------------------===//