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8476e6e250
In LLVM IR the following code:
%r = urem <ty> %t, %b
is equivalent to:
%q = udiv <ty> %t, %b
%s = mul <ty> nuw %q, %b
%r = sub <ty> nuw %t, %q ; (t / b) * b + (t % b) = t
As UDiv, Mul and Sub are already supported by SCEV, URem can be
implemented with minimal effort this way.
Note: While SRem and SDiv are also related this way, SCEV does not
provides SDiv yet.
llvm-svn: 306695
16 lines
299 B
LLVM
16 lines
299 B
LLVM
; RUN: opt < %s -scalar-evolution -analyze | FileCheck %s
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define i8 @foo(i8 %a) {
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%t0 = urem i8 %a, 27
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; CHECK: %t0
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; CHECK-NEXT: --> ((-27 * (%a /u 27)) + %a)
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ret i8 %t0
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}
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define i8 @bar(i8 %a) {
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%t1 = urem i8 %a, 1
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; CHECK: %t1
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; CHECK-NEXT: --> 0
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ret i8 %t1
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}
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