llvm-6502/test/Transforms/IndVarSimplify/udiv.ll
Dan Gohman ca9b7037e2 Suppress LinearFunctionTestReplace when the computed backedge-taken
expression is a UDiv and it doesn't appear that the UDiv came from
the user's source.

ScalarEvolution has recently figured out how to compute a tripcount
expression for the inner loop in
SingleSource/Benchmarks/Shootout/sieve.c, using a udiv. Emitting a
udiv instruction dramatically slows down the enclosing loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101068 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12 21:13:43 +00:00

163 lines
7.6 KiB
LLVM

; RUN: opt -indvars -S < %s | FileCheck %s
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-n8:16:32:64"
@main.flags = internal global [8193 x i8] zeroinitializer, align 1 ; <[8193 x i8]*> [#uses=5]
@.str = private constant [11 x i8] c"Count: %d\0A\00" ; <[11 x i8]*> [#uses=1]
; Indvars shouldn't emit a udiv here, because there's no udiv in the
; original code. This comes from SingleSource/Benchmarks/Shootout/sieve.c.
; CHECK: @main
; CHECK-NOT: div
define i32 @main(i32 %argc, i8** nocapture %argv) nounwind {
entry:
%cmp = icmp eq i32 %argc, 2 ; <i1> [#uses=1]
br i1 %cmp, label %cond.true, label %while.cond.preheader
cond.true: ; preds = %entry
%arrayidx = getelementptr inbounds i8** %argv, i64 1 ; <i8**> [#uses=1]
%tmp2 = load i8** %arrayidx ; <i8*> [#uses=1]
%call = tail call i32 @atoi(i8* %tmp2) nounwind readonly ; <i32> [#uses=1]
br label %while.cond.preheader
while.cond.preheader: ; preds = %entry, %cond.true
%NUM.0.ph = phi i32 [ %call, %cond.true ], [ 170000, %entry ] ; <i32> [#uses=2]
%tobool18 = icmp eq i32 %NUM.0.ph, 0 ; <i1> [#uses=1]
br i1 %tobool18, label %while.end, label %bb.nph30
while.cond.loopexit: ; preds = %for.cond12.while.cond.loopexit_crit_edge, %for.cond12.loopexit
%count.2.lcssa = phi i32 [ %count.1.lcssa, %for.cond12.while.cond.loopexit_crit_edge ], [ 0, %for.cond12.loopexit ] ; <i32> [#uses=1]
br label %while.cond
while.cond: ; preds = %while.cond.loopexit
%tobool = icmp eq i32 %dec19, 0 ; <i1> [#uses=1]
br i1 %tobool, label %while.cond.while.end_crit_edge, label %for.cond.preheader
while.cond.while.end_crit_edge: ; preds = %while.cond
%count.2.lcssa.lcssa = phi i32 [ %count.2.lcssa, %while.cond ] ; <i32> [#uses=1]
br label %while.end
bb.nph30: ; preds = %while.cond.preheader
br label %for.cond.preheader
for.cond.preheader: ; preds = %bb.nph30, %while.cond
%dec19.in = phi i32 [ %NUM.0.ph, %bb.nph30 ], [ %dec19, %while.cond ] ; <i32> [#uses=1]
%dec19 = add i32 %dec19.in, -1 ; <i32> [#uses=2]
br i1 true, label %bb.nph, label %for.cond12.loopexit
for.cond: ; preds = %for.body
%cmp8 = icmp slt i64 %inc, 8193 ; <i1> [#uses=1]
br i1 %cmp8, label %for.body, label %for.cond.for.cond12.loopexit_crit_edge
for.cond.for.cond12.loopexit_crit_edge: ; preds = %for.cond
br label %for.cond12.loopexit
bb.nph: ; preds = %for.cond.preheader
br label %for.body
for.body: ; preds = %bb.nph, %for.cond
%i.02 = phi i64 [ 2, %bb.nph ], [ %inc, %for.cond ] ; <i64> [#uses=2]
%arrayidx10 = getelementptr inbounds [8193 x i8]* @main.flags, i64 0, i64 %i.02 ; <i8*> [#uses=1]
store i8 1, i8* %arrayidx10
%inc = add nsw i64 %i.02, 1 ; <i64> [#uses=2]
br label %for.cond
for.cond12.loopexit: ; preds = %for.cond.for.cond12.loopexit_crit_edge, %for.cond.preheader
br i1 true, label %bb.nph16, label %while.cond.loopexit
for.cond12: ; preds = %for.inc35
%cmp14 = icmp slt i64 %inc37, 8193 ; <i1> [#uses=1]
br i1 %cmp14, label %for.body15, label %for.cond12.while.cond.loopexit_crit_edge
for.cond12.while.cond.loopexit_crit_edge: ; preds = %for.cond12
%count.1.lcssa = phi i32 [ %count.1, %for.cond12 ] ; <i32> [#uses=1]
br label %while.cond.loopexit
bb.nph16: ; preds = %for.cond12.loopexit
br label %for.body15
for.body15: ; preds = %bb.nph16, %for.cond12
%count.212 = phi i32 [ 0, %bb.nph16 ], [ %count.1, %for.cond12 ] ; <i32> [#uses=2]
%i.17 = phi i64 [ 2, %bb.nph16 ], [ %inc37, %for.cond12 ] ; <i64> [#uses=4]
%arrayidx17 = getelementptr inbounds [8193 x i8]* @main.flags, i64 0, i64 %i.17 ; <i8*> [#uses=1]
%tmp18 = load i8* %arrayidx17 ; <i8> [#uses=1]
%tobool19 = icmp eq i8 %tmp18, 0 ; <i1> [#uses=1]
br i1 %tobool19, label %for.inc35, label %if.then
if.then: ; preds = %for.body15
%add = shl i64 %i.17, 1 ; <i64> [#uses=2]
%cmp243 = icmp slt i64 %add, 8193 ; <i1> [#uses=1]
br i1 %cmp243, label %bb.nph5, label %for.end32
for.cond22: ; preds = %for.body25
%cmp24 = icmp slt i64 %add31, 8193 ; <i1> [#uses=1]
br i1 %cmp24, label %for.body25, label %for.cond22.for.end32_crit_edge
for.cond22.for.end32_crit_edge: ; preds = %for.cond22
br label %for.end32
bb.nph5: ; preds = %if.then
br label %for.body25
for.body25: ; preds = %bb.nph5, %for.cond22
%k.04 = phi i64 [ %add, %bb.nph5 ], [ %add31, %for.cond22 ] ; <i64> [#uses=2]
%arrayidx27 = getelementptr inbounds [8193 x i8]* @main.flags, i64 0, i64 %k.04 ; <i8*> [#uses=1]
store i8 0, i8* %arrayidx27
%add31 = add nsw i64 %k.04, %i.17 ; <i64> [#uses=2]
br label %for.cond22
for.end32: ; preds = %for.cond22.for.end32_crit_edge, %if.then
%inc34 = add nsw i32 %count.212, 1 ; <i32> [#uses=1]
br label %for.inc35
for.inc35: ; preds = %for.body15, %for.end32
%count.1 = phi i32 [ %inc34, %for.end32 ], [ %count.212, %for.body15 ] ; <i32> [#uses=2]
%inc37 = add nsw i64 %i.17, 1 ; <i64> [#uses=2]
br label %for.cond12
while.end: ; preds = %while.cond.while.end_crit_edge, %while.cond.preheader
%count.0.lcssa = phi i32 [ %count.2.lcssa.lcssa, %while.cond.while.end_crit_edge ], [ 0, %while.cond.preheader ] ; <i32> [#uses=1]
%call40 = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([11 x i8]* @.str, i64 0, i64 0), i32 %count.0.lcssa) nounwind ; <i32> [#uses=0]
ret i32 0
}
declare i32 @atoi(i8* nocapture) nounwind readonly
declare i32 @printf(i8* nocapture, ...) nounwind
; IndVars shouldn't be afraid to emit a udiv here, since there's a udiv in
; the original code.
; CHECK: @foo
; CHECK: for.body.preheader:
; CHECK-NEXT: udiv
define void @foo(double* %p, i64 %n) nounwind {
entry:
%div0 = udiv i64 %n, 7 ; <i64> [#uses=1]
%div1 = add i64 %div0, 1
%cmp2 = icmp ult i64 0, %div1 ; <i1> [#uses=1]
br i1 %cmp2, label %for.body.preheader, label %for.end
for.body.preheader: ; preds = %entry
br label %for.body
for.body: ; preds = %for.body.preheader, %for.body
%i.03 = phi i64 [ %inc, %for.body ], [ 0, %for.body.preheader ] ; <i64> [#uses=2]
%arrayidx = getelementptr inbounds double* %p, i64 %i.03 ; <double*> [#uses=1]
store double 0.000000e+00, double* %arrayidx
%inc = add i64 %i.03, 1 ; <i64> [#uses=2]
%divx = udiv i64 %n, 7 ; <i64> [#uses=1]
%div = add i64 %divx, 1
%cmp = icmp ult i64 %inc, %div ; <i1> [#uses=1]
br i1 %cmp, label %for.body, label %for.end.loopexit
for.end.loopexit: ; preds = %for.body
br label %for.end
for.end: ; preds = %for.end.loopexit, %entry
ret void
}