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ScalarEvolution: do not set nuw when creating exprs of form <expr> + …
…<all-ones>. The nuw constraint will not be satisfied unless <expr> == 0. This bug has been around since r102234 (in 2010!), but was uncovered by r251052, which introduced more aggressive optimization of nuw scev expressions. Differential Revision: http://reviews.llvm.org/D14850 llvm-svn: 253627
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; RUN: opt -indvars -S %s | FileCheck %s | ||
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%struct.A = type { i8 } | ||
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@c = global %struct.A* null | ||
@d = global i32 4 | ||
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define void @_Z3fn1v() { | ||
%x2 = load i32, i32* @d | ||
%x3 = icmp slt i32 %x2, 1 | ||
%x4 = select i1 %x3, i32 1, i32 %x2 | ||
%x5 = load %struct.A*, %struct.A** @c | ||
%j.sroa.0.0..sroa_idx = getelementptr %struct.A, %struct.A* %x5, i64 0, i32 0 | ||
%j.sroa.0.0.copyload = load i8, i8* %j.sroa.0.0..sroa_idx | ||
br label %.preheader4.lr.ph | ||
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.preheader4.lr.ph: ; preds = %0 | ||
; CHECK-NOT: add i64 {{.*}}, 4294967296 | ||
br label %.preheader4 | ||
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.preheader4: ; preds = %x22, %.preheader4.lr.ph | ||
%k.09 = phi i8* [ undef, %.preheader4.lr.ph ], [ %x25, %x22 ] | ||
%x8 = icmp ult i32 0, 4 | ||
br i1 %x8, label %.preheader.lr.ph, label %x22 | ||
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.preheader.lr.ph: ; preds = %.preheader4 | ||
br label %.preheader | ||
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.preheader: ; preds = %x17, %.preheader.lr.ph | ||
%k.17 = phi i8* [ %k.09, %.preheader.lr.ph ], [ %x19, %x17 ] | ||
%v.06 = phi i32 [ 0, %.preheader.lr.ph ], [ %x20, %x17 ] | ||
br label %x17 | ||
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x17: ; preds = %.preheader | ||
%x18 = sext i8 %j.sroa.0.0.copyload to i64 | ||
%x19 = getelementptr i8, i8* %k.17, i64 %x18 | ||
%x20 = add i32 %v.06, 1 | ||
%x21 = icmp ult i32 %x20, %x4 | ||
br i1 %x21, label %.preheader, label %._crit_edge.8 | ||
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._crit_edge.8: ; preds = %x17 | ||
%split = phi i8* [ %x19, %x17 ] | ||
br label %x22 | ||
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x22: ; preds = %._crit_edge.8, %.preheader4 | ||
%k.1.lcssa = phi i8* [ %split, %._crit_edge.8 ], [ %k.09, %.preheader4 ] | ||
%x25 = getelementptr i8, i8* %k.1.lcssa | ||
br label %.preheader4 | ||
} |