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01ecca20bf
information to simplify [sz]ext({a,+,b}) to {zext(a),+,[zs]ext(b)},
as appropriate.
These functions and the trip count code each call into the other, so
this requires careful handling to avoid infinite recursion. During
the initial trip count computation, conservative SCEVs are used,
which are subsequently discarded once the trip count is actually
known.
Among other benefits, this change lets LSR automatically eliminate
some unnecessary zext-inreg and sext-inreg operation where the
operand is an induction variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70241 91177308-0d34-0410-b5e6-96231b3b80d8
27 lines
1.0 KiB
LLVM
27 lines
1.0 KiB
LLVM
; RUN: llvm-as < %s | llc --x86-asm-syntax=att | grep {cmpq \$8}
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target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
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target triple = "x86_64-apple-darwin9"
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; This is like change-compare-stride-trickiness-0.ll except the comparison
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; happens after the relevant use, so the comparison stride can be
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; easily changed.
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define void @foo() nounwind {
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entry:
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br label %loop
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loop:
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%indvar = phi i32 [ 0, %entry ], [ %i.2.0.us1534, %loop ] ; <i32> [#uses=1]
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%i.2.0.us1534 = add i32 %indvar, 1 ; <i32> [#uses=3]
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%tmp628.us1540 = shl i32 %i.2.0.us1534, 1 ; <i32> [#uses=1]
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%tmp645646647.us1547 = sext i32 %tmp628.us1540 to i64 ; <i64> [#uses=1]
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store i64 %tmp645646647.us1547, i64* null
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%tmp611.us1535 = icmp eq i32 %i.2.0.us1534, 4 ; <i1> [#uses=2]
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%tmp623.us1538 = select i1 %tmp611.us1535, i32 6, i32 0 ; <i32> [#uses=1]
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store i32 %tmp623.us1538, i32* null
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br i1 %tmp611.us1535, label %exit, label %loop
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exit:
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ret void
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}
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