Register allocator: add condition to hoist a spill to outer loop.

We make sure a spill is not hoisted to a hotter outer loop by adding
a condition. Hoist a spill to outer loop if there are multiple dependents
(it can be beneficial if more than one dependents are hoisted) or
if DepSV (the hoisting source) is hotter than SV (the hoisting destination).

rdar://16268194


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204522 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 389 insertions, 0 deletions

diff --git a/test/CodeGen/X86/ragreedy-hoist-spill.ll b/test/CodeGen/X86/ragreedy-hoist-spill.ll
new file mode 100644
index 0000000000..c6b28f71af
--- /dev/null
+++ b/test/CodeGen/X86/ragreedy-hoist-spill.ll
@@ -0,0 +1,389 @@
+; RUN: llc < %s -mtriple=x86_64-apple-macosx -regalloc=greedy | FileCheck %s
+
+; This testing case is reduced from 254.gap SyFgets funciton.
+; We make sure a spill is not hoisted to a hotter outer loop.
+
+%struct.TMP.1 = type { %struct.TMP.2*, %struct.TMP.2*, [1024 x i8] }
+%struct.TMP.2 = type { i8*, i32, i32, i16, i16, %struct.TMP.3, i32, i8*, i32 (i8*)*, i32 (i8*, i8*, i32)*, i64 (i8*, i64, i32)*, i32 (i8*, i8*, i32)*, %struct.TMP.3, %struct.TMP.4*, i32, [3 x i8], [1 x i8], %struct.TMP.3, i32, i64 }
+%struct.TMP.4 = type opaque
+%struct.TMP.3 = type { i8*, i32 }
+
+@syBuf = external global [16 x %struct.TMP.1], align 16
+@syHistory = external global [8192 x i8], align 16
+@SyFgets.yank = external global [512 x i8], align 16
+@syCTRO = external global i32, align 4
+
+; CHECK-LABEL: SyFgets
+define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
+entry:
+  %sub.ptr.rhs.cast646 = ptrtoint i8* %line to i64
+  %old = alloca [512 x i8], align 16
+  %0 = getelementptr inbounds [512 x i8]* %old, i64 0, i64 0
+  switch i64 %fid, label %if.then [
+    i64 2, label %if.end
+    i64 0, label %if.end
+  ]
+
+if.then:
+  br label %cleanup
+
+if.end:
+  switch i64 undef, label %if.end25 [
+    i64 0, label %if.then4
+    i64 1, label %land.lhs.true14
+  ]
+
+if.then4:
+  br i1 undef, label %SyTime.exit, label %if.then.i
+
+if.then.i:
+  unreachable
+
+SyTime.exit:
+  br i1 undef, label %SyTime.exit2681, label %if.then.i2673
+
+if.then.i2673:
+  unreachable
+
+SyTime.exit2681:
+  br label %cleanup
+
+land.lhs.true14:
+  unreachable
+
+if.end25:
+  br i1 undef, label %SyTime.exit2720, label %if.then.i2712
+
+if.then.i2712:
+  unreachable
+
+SyTime.exit2720:
+  %add.ptr = getelementptr [512 x i8]* %old, i64 0, i64 512
+  %cmp293427 = icmp ult i8* %0, %add.ptr
+  br i1 %cmp293427, label %for.body.lr.ph, label %while.body.preheader
+
+for.body.lr.ph:
+  call void @llvm.memset.p0i8.i64(i8* undef, i8 32, i64 512, i32 16, i1 false)
+  br label %while.body.preheader
+
+while.body.preheader:
+  %add.ptr1603 = getelementptr [512 x i8]* null, i64 0, i64 512
+  %echo.i3101 = getelementptr [16 x %struct.TMP.1]* @syBuf, i64 0, i64 %fid, i32 1
+  %1 = xor i64 %sub.ptr.rhs.cast646, -1
+  br label %do.body
+
+do.body:
+  %ch2.0 = phi i32 [ 0, %while.body.preheader ], [ %ch.12.ch2.12, %do.body ]
+  %rep.0 = phi i32 [ 1, %while.body.preheader ], [ %rep.6, %do.body ]
+  store i32 0, i32* @syCTRO, align 4, !tbaa !1
+  %ch.0.ch2.0 = select i1 undef, i32 14, i32 %ch2.0
+  %ch2.2 = select i1 undef, i32 0, i32 %ch.0.ch2.0
+  %ch.2.ch2.2 = select i1 undef, i32 0, i32 %ch2.2
+  %ch2.4 = select i1 undef, i32 278, i32 %ch.2.ch2.2
+  %ch2.5 = select i1 undef, i32 0, i32 %ch2.4
+  %rep.2 = select i1 undef, i32 undef, i32 %rep.0
+  %ch.5.ch2.5 = select i1 undef, i32 undef, i32 %ch2.5
+  %ch2.7 = select i1 undef, i32 0, i32 %ch.5.ch2.5
+  %rep.3 = select i1 undef, i32 undef, i32 %rep.2
+  %ch.7.ch2.7 = select i1 false, i32 0, i32 %ch2.7
+  %mul98.rep.3 = select i1 false, i32 0, i32 %rep.3
+  %ch2.9 = select i1 undef, i32 undef, i32 %ch.7.ch2.7
+  %rep.5 = select i1 undef, i32 undef, i32 %mul98.rep.3
+  %ch2.10 = select i1 false, i32 undef, i32 %ch2.9
+  %rep.6 = select i1 false, i32 undef, i32 %rep.5
+  %isdigittmp = add i32 %ch2.10, -48
+  %isdigit = icmp ult i32 %isdigittmp, 10
+  %cmp119 = icmp eq i32 undef, 22
+  %or.cond1875 = and i1 %isdigit, %cmp119
+  %ch.10.ch2.10 = select i1 %or.cond1875, i32 undef, i32 %ch2.10
+  %.ch.10 = select i1 %or.cond1875, i32 0, i32 undef
+  %ch2.12 = select i1 undef, i32 %.ch.10, i32 %ch.10.ch2.10
+  %ch.12 = select i1 undef, i32 0, i32 %.ch.10
+  %ch.12.ch2.12 = select i1 false, i32 %ch.12, i32 %ch2.12
+  %.ch.12 = select i1 false, i32 0, i32 %ch.12
+  %cmp147 = icmp eq i32 %.ch.12, 0
+  br i1 %cmp147, label %do.body, label %do.end
+
+do.end:
+  %cmp164 = icmp eq i32 %ch.12.ch2.12, 21
+  %mul167 = shl i32 %rep.6, 2
+  %rep.8 = select i1 %cmp164, i32 %mul167, i32 %rep.6
+  %..ch.19 = select i1 false, i32 2, i32 0
+  br i1 undef, label %while.body200, label %while.end1465
+
+while.body200:
+  %dec3386.in = phi i32 [ %dec3386, %while.cond197.backedge ], [ %rep.8, %do.end ]
+  %oldc.13384 = phi i32 [ %oldc.1.be, %while.cond197.backedge ], [ 0, %do.end ]
+  %ch.213379 = phi i32 [ %last.1.be, %while.cond197.backedge ], [ %..ch.19, %do.end ]
+  %last.13371 = phi i32 [ %last.1.be, %while.cond197.backedge ], [ 0, %do.end ]
+  %dec3386 = add i32 %dec3386.in, -1
+  switch i32 %ch.213379, label %sw.default [
+    i32 1, label %while.cond201.preheader
+    i32 322, label %sw.bb206
+    i32 354, label %sw.bb206
+    i32 2, label %sw.bb243
+    i32 364, label %sw.bb1077
+    i32 326, label %sw.bb256
+    i32 358, label %sw.bb256
+    i32 341, label %sw.bb979
+    i32 323, label %while.cond1037.preheader
+    i32 373, label %sw.bb979
+    i32 4, label %if.then1477
+    i32 332, label %sw.bb1077
+    i32 11, label %for.cond357
+    i32 355, label %while.cond1037.preheader
+    i32 324, label %sw.bb474
+    i32 356, label %sw.bb474
+    i32 20, label %sw.bb566
+    i32 -1, label %while.cond197.backedge
+    i32 268, label %sw.bb1134
+    i32 16, label %while.cond635.preheader
+    i32 18, label %sw.bb956
+    i32 316, label %while.cond864
+  ]
+
+while.cond1037.preheader:
+  %cmp10393273 = icmp eq i8 undef, 0
+  br i1 %cmp10393273, label %if.end1070, label %land.rhs1041
+
+while.cond635.preheader:
+  br i1 undef, label %for.body643.us, label %while.cond661
+
+for.body643.us:
+  br label %for.body643.us
+
+while.cond201.preheader:
+  %umax = select i1 false, i64 undef, i64 %1
+  %2 = xor i64 %umax, -1
+  %3 = inttoptr i64 %2 to i8*
+  br label %while.cond197.backedge
+
+sw.bb206:
+  br label %while.cond197.backedge
+
+sw.bb243:
+  br label %while.cond197.backedge
+
+sw.bb256:
+  br label %while.cond197.backedge
+
+while.cond197.backedge:
+  %last.1.be = phi i32 [ %ch.213379, %sw.default ], [ -1, %while.body200 ], [ %ch.213379, %sw.bb1077 ], [ %ch.213379, %sw.bb979 ], [ 18, %sw.bb956 ], [ 20, %sw.bb566 ], [ %ch.213379, %for.end552 ], [ %ch.213379, %sw.bb256 ], [ 2, %sw.bb243 ], [ 1, %while.cond201.preheader ], [ 268, %for.cond1145.preheader ], [ %ch.213379, %sw.bb206 ]
+  %oldc.1.be = phi i32 [ %oldc.13384, %sw.default ], [ %oldc.13384, %while.body200 ], [ %oldc.13384, %sw.bb1077 ], [ %oldc.13384, %sw.bb979 ], [ %oldc.13384, %sw.bb956 ], [ %oldc.13384, %sw.bb566 ], [ %oldc.13384, %for.end552 ], [ %oldc.13384, %sw.bb256 ], [ %oldc.13384, %sw.bb243 ], [ %oldc.13384, %while.cond201.preheader ], [ 0, %for.cond1145.preheader ], [ %oldc.13384, %sw.bb206 ]
+  %cmp198 = icmp sgt i32 %dec3386, 0
+  br i1 %cmp198, label %while.body200, label %while.end1465
+
+for.cond357:
+  br label %for.cond357
+
+sw.bb474:
+  %cmp476 = icmp eq i8 undef, 0
+  br i1 %cmp476, label %if.end517, label %do.body479.preheader
+
+do.body479.preheader:
+  %cmp4833314 = icmp eq i8 undef, 0
+  br i1 %cmp4833314, label %if.end517, label %land.rhs485
+
+land.rhs485:
+  %incdec.ptr4803316 = phi i8* [ %incdec.ptr480, %do.body479.backedge.land.rhs485_crit_edge ], [ undef, %do.body479.preheader ]
+  %isascii.i.i27763151 = icmp sgt i8 undef, -1
+  br i1 %isascii.i.i27763151, label %cond.true.i.i2780, label %cond.false.i.i2782
+
+cond.true.i.i2780:
+  br i1 undef, label %land.lhs.true490, label %lor.rhs500
+
+cond.false.i.i2782:
+  unreachable
+
+land.lhs.true490:
+  br i1 false, label %lor.rhs500, label %do.body479.backedge
+
+lor.rhs500:
+  ; CHECK: lor.rhs500
+  ; Make sure that we don't hoist the spill to outer loops.
+  ; CHECK: movq %r{{.*}}, {{[0-9]+}}(%rsp)
+  ; CHECK: movq %r{{.*}}, {{[0-9]+}}(%rsp)
+  ; CHECK: callq {{.*}}maskrune
+  %call3.i.i2792 = call i32 @__maskrune(i32 undef, i64 256)
+  br i1 undef, label %land.lhs.true504, label %do.body479.backedge
+
+land.lhs.true504:
+  br i1 undef, label %do.body479.backedge, label %if.end517
+
+do.body479.backedge:
+  %incdec.ptr480 = getelementptr i8* %incdec.ptr4803316, i64 1
+  %cmp483 = icmp eq i8 undef, 0
+  br i1 %cmp483, label %if.end517, label %do.body479.backedge.land.rhs485_crit_edge
+
+do.body479.backedge.land.rhs485_crit_edge:
+  br label %land.rhs485
+
+if.end517:
+  %q.4 = phi i8* [ undef, %sw.bb474 ], [ undef, %do.body479.preheader ], [ %incdec.ptr480, %do.body479.backedge ], [ %incdec.ptr4803316, %land.lhs.true504 ]
+  switch i32 %last.13371, label %if.then532 [
+    i32 383, label %for.cond534
+    i32 356, label %for.cond534
+    i32 324, label %for.cond534
+    i32 24, label %for.cond534
+    i32 11, label %for.cond534
+  ]
+
+if.then532:
+  store i8 0, i8* getelementptr inbounds ([512 x i8]* @SyFgets.yank, i64 0, i64 0), align 16, !tbaa !5
+  br label %for.cond534
+
+for.cond534:
+  %cmp536 = icmp eq i8 undef, 0
+  br i1 %cmp536, label %for.cond542.preheader, label %for.cond534
+
+for.cond542.preheader:
+  br i1 undef, label %for.body545, label %for.end552
+
+for.body545:
+  br i1 undef, label %for.end552, label %for.body545
+
+for.end552:
+  %s.2.lcssa = phi i8* [ undef, %for.cond542.preheader ], [ %q.4, %for.body545 ]
+  %sub.ptr.lhs.cast553 = ptrtoint i8* %s.2.lcssa to i64
+  %sub.ptr.sub555 = sub i64 %sub.ptr.lhs.cast553, 0
+  %arrayidx556 = getelementptr i8* null, i64 %sub.ptr.sub555
+  store i8 0, i8* %arrayidx556, align 1, !tbaa !5
+  br label %while.cond197.backedge
+
+sw.bb566:
+  br label %while.cond197.backedge
+
+while.cond661:
+  br label %while.cond661
+
+while.cond864:
+  br label %while.cond864
+
+sw.bb956:
+  br i1 undef, label %if.then959, label %while.cond197.backedge
+
+if.then959:
+  br label %while.cond962
+
+while.cond962:
+  br label %while.cond962
+
+sw.bb979:
+  br label %while.cond197.backedge
+
+land.rhs1041:
+  unreachable
+
+if.end1070:
+  br label %sw.bb1077
+
+sw.bb1077:
+  br label %while.cond197.backedge
+
+sw.bb1134:
+  br i1 false, label %for.body1139, label %for.cond1145.preheader
+
+for.cond1145.preheader:
+  br i1 %cmp293427, label %for.body1150.lr.ph, label %while.cond197.backedge
+
+for.body1150.lr.ph:
+  unreachable
+
+for.body1139:
+  unreachable
+
+sw.default:
+  br label %while.cond197.backedge
+
+while.end1465:
+  %oldc.1.lcssa = phi i32 [ 0, %do.end ], [ %oldc.1.be, %while.cond197.backedge ]
+  %ch.21.lcssa = phi i32 [ %..ch.19, %do.end ], [ %last.1.be, %while.cond197.backedge ]
+  switch i32 %ch.21.lcssa, label %for.cond1480.preheader [
+    i32 -1, label %if.then1477
+    i32 15, label %if.then1477
+    i32 13, label %if.then1477
+    i32 10, label %if.then1477
+  ]
+
+for.cond1480.preheader:
+  br i1 undef, label %for.body1606.lr.ph, label %for.end1609
+
+if.then1477:
+  %p.1.lcssa3539 = phi i8* [ null, %while.end1465 ], [ null, %while.end1465 ], [ null, %while.end1465 ], [ null, %while.end1465 ], [ %line, %while.body200 ]
+  %call1.i3057 = call i64 @"\01_write"(i32 undef, i8* undef, i64 1)
+  %sub.ptr.lhs.cast1717 = ptrtoint i8* %p.1.lcssa3539 to i64
+  %sub.ptr.sub1719 = sub i64 %sub.ptr.lhs.cast1717, %sub.ptr.rhs.cast646
+  %idx.neg1727 = sub i64 0, %sub.ptr.sub1719
+  br label %for.body1723
+
+for.body1606.lr.ph:
+  br label %for.end1609
+
+for.end1609:
+  br i1 undef, label %for.cond1659.preheader, label %land.lhs.true1614
+
+land.lhs.true1614:
+  br label %for.cond1659.preheader
+
+for.cond1659.preheader:
+  %cmp16623414 = icmp ult i8* undef, %add.ptr1603
+  br i1 %cmp16623414, label %for.body1664.lr.ph, label %while.body1703.lr.ph
+
+for.body1664.lr.ph:
+  %cmp16773405 = icmp slt i64 undef, undef
+  br i1 %cmp16773405, label %while.body1679, label %while.cond1683.preheader
+
+while.body1703.lr.ph:
+  unreachable
+
+while.cond1683.preheader:
+  br i1 undef, label %while.body1691, label %while.end1693
+
+while.body1679:
+  %oldc.43406 = phi i32 [ %inc, %syEchoch.exit3070 ], [ %oldc.1.lcssa, %for.body1664.lr.ph ]
+  %4 = load %struct.TMP.2** %echo.i3101, align 8, !tbaa !6
+  %call.i3062 = call i32 @fileno(%struct.TMP.2* %4)
+  br i1 undef, label %if.then.i3069, label %syEchoch.exit3070
+
+if.then.i3069:
+  br label %syEchoch.exit3070
+
+syEchoch.exit3070:
+  %inc = add i32 %oldc.43406, 1
+  %conv1672 = sext i32 %inc to i64
+  %cmp1677 = icmp slt i64 %conv1672, undef
+  br i1 %cmp1677, label %while.body1679, label %while.cond1683.preheader
+
+while.body1691:
+  unreachable
+
+while.end1693:
+  unreachable
+
+for.body1723:
+  %q.303203 = phi i8* [ getelementptr inbounds ([8192 x i8]* @syHistory, i64 0, i64 8189), %if.then1477 ], [ %incdec.ptr1730, %for.body1723 ]
+  %add.ptr1728 = getelementptr i8* %q.303203, i64 %idx.neg1727
+  %5 = load i8* %add.ptr1728, align 1, !tbaa !5
+  %incdec.ptr1730 = getelementptr i8* %q.303203, i64 -1
+  br label %for.body1723
+
+cleanup:
+  ret i8* undef
+}
+
+declare i32 @fileno(%struct.TMP.2* nocapture)
+declare i64 @"\01_write"(i32, i8*, i64)
+declare i32 @__maskrune(i32, i64)
+declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1)
+
+!llvm.ident = !{!0}
+
+!0 = metadata !{metadata !"clang version 3.5.0 (trunk 204257)"}
+!1 = metadata !{metadata !2, metadata !2, i64 0}
+!2 = metadata !{metadata !"int", metadata !3, i64 0}
+!3 = metadata !{metadata !"omnipotent char", metadata !4, i64 0}
+!4 = metadata !{metadata !"Simple C/C++ TBAA"}
+!5 = metadata !{metadata !3, metadata !3, i64 0}
+!6 = metadata !{metadata !7, metadata !8, i64 8}
+!7 = metadata !{metadata !"", metadata !8, i64 0, metadata !8, i64 8, metadata !3, i64 16}
+!8 = metadata !{metadata !"any pointer", metadata !3, i64 0}