[mips] Do not place users of $ra in the delay slot of call instructions.

Summary:
When we are trying to fill the delay slot of a call instruction, we must avoid
filler instructions that use the $ra register. This fixes the test
MultiSource/Applications/JM/lencod when we enable the forward delay slot filler.

Reviewers: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9670

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237362 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsDelaySlotFiller.cpp b/lib/Target/Mips/MipsDelaySlotFiller.cpp
index de9f4a59e011fce993b87c3642229e2734cf8b10..4faeb33216214917225070709fbff073a2266cfc 100644 (file)
--- a/lib/Target/Mips/MipsDelaySlotFiller.cpp
+++ b/lib/Target/Mips/MipsDelaySlotFiller.cpp
@@ -315,6 +315,14 @@ void RegDefsUses::init(const MachineInstr &MI) {
 void RegDefsUses::setCallerSaved(const MachineInstr &MI) {
   assert(MI.isCall());
 
+  // Add RA/RA_64 to Defs to prevent users of RA/RA_64 from going into
+  // the delay slot. The reason is that RA/RA_64 must not be changed
+  // in the delay slot so that the callee can return to the caller.
+  if (MI.definesRegister(Mips::RA) || MI.definesRegister(Mips::RA_64)) {
+    Defs.set(Mips::RA);
+    Defs.set(Mips::RA_64);
+  }
+
   // If MI is a call, add all caller-saved registers to Defs.
   BitVector CallerSavedRegs(TRI.getNumRegs(), true);
 

diff --git a/test/CodeGen/Mips/delay-slot-fill-forward.ll b/test/CodeGen/Mips/delay-slot-fill-forward.ll
new file mode 100644 (file)
index 0000000..7fc011d
--- /dev/null
+++ b/test/CodeGen/Mips/delay-slot-fill-forward.ll
@@ -0,0 +1,183 @@
+; RUN: llc < %s -march=mips -mcpu=mips32r2 -O2 \
+; RUN:     -disable-mips-df-forward-search=false \
+; RUN:     -disable-mips-df-succbb-search=false \
+; RUN:     -relocation-model=static | FileCheck %s
+
+; This test was generated with bugpoint from
+; MultiSource/Applications/JM/lencod/me_fullsearch.c
+
+%struct.SubImageContainer = type { i16****, [2 x i16****] }
+%struct.storable_picture = type { i32, i32, i32, i32, i32, i32,
+  [6 x [33 x i64]], [6 x [33 x i64]], [6 x [33 x i64]], [6 x [33 x i64]],
+  i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32,
+  i32, i32, i32, i32, i32, i16**, i16****, i16****, i16*****, i16***,
+  i8*, i8***, i64***, i64***, i16****, i8**, i8**, %struct.storable_picture*,
+  %struct.storable_picture*, %struct.storable_picture*,
+  i32, i32, i32, i32, i32, i32, i32 }
+
+@img_height = external global i16, align 2
+@width_pad = external global i32, align 4
+@height_pad = external global i32, align 4
+@mvbits = external global i32*, align 4
+@ref_pic1_sub = external global %struct.SubImageContainer, align 4
+@ref_pic2_sub = external global %struct.SubImageContainer, align 4
+@wbp_weight = external global i32****, align 4
+@weight1 = external global i16, align 2
+@weight2 = external global i16, align 2
+@offsetBi = external global i16, align 2
+@computeBiPred2 = external global [3 x i32 (i16*, i32, i32, i32, i32, i32, i32, i32)*], align 4
+@computeBiPred = external global i32 (i16*, i32, i32, i32, i32, i32, i32, i32)*, align 4
+@bipred2_access_method = external global i32, align 4
+@start_me_refinement_hp = external global i32, align 4
+
+declare i32 @foobar(i16*, i32 signext , i32 signext , i32 signext ,
+                    i32 signext , i32 signext , i32 signext , i32 signext ) #1
+
+define void @SubPelBlockSearchBiPred(i16* %orig_pic, i16 signext %ref,
+    i32 signext %pic_pix_x, i32 signext %pic_pix_y, i16 signext %pred_mv_y,
+    i16* nocapture %mv_x, i16* nocapture %mv_y, i16* nocapture readonly %s_mv_x,
+    i32 signext %search_pos2, i32 signext %min_mcost) #0 {
+; CHECK-LABEL: SubPelBlockSearchBiPred:
+entry:
+  %add40 = shl i32 %pic_pix_x, 2
+  %shl = add i32 %add40, 80
+  %add41 = shl i32 %pic_pix_y, 2
+  %0 = load i32, i32* @start_me_refinement_hp, align 4, !tbaa !1
+  %cond47 = select i1 undef, i32 1, i32 %search_pos2
+  %1 = load i16, i16* %s_mv_x, align 2, !tbaa !5
+  %conv48 = sext i16 %1 to i32
+  %add49 = add nsw i32 %conv48, %shl
+  %idxprom52 = sext i16 %ref to i32
+  %2 = load i32, i32* null, align 4, !tbaa !1
+  store i32 undef, i32* bitcast (%struct.SubImageContainer* @ref_pic1_sub to i32*), align 4, !tbaa !7
+  %3 = load i32, i32* undef, align 4, !tbaa !10
+  store i32 %3, i32* bitcast (%struct.SubImageContainer* @ref_pic2_sub to i32*), align 4, !tbaa !7
+  store i16 0, i16* @img_height, align 2, !tbaa !5
+  %size_x_pad = getelementptr inbounds %struct.storable_picture, %struct.storable_picture* null, i32 0, i32 22
+  %4 = load i32, i32* %size_x_pad, align 4, !tbaa !12
+  store i32 %4, i32* @width_pad, align 4, !tbaa !1
+  %5 = load i32, i32* undef, align 4, !tbaa !13
+  store i32 %5, i32* @height_pad, align 4, !tbaa !1
+  %6 = load i32****, i32***** @wbp_weight, align 4, !tbaa !14
+  %arrayidx75 = getelementptr inbounds i32***, i32**** %6, i32 undef
+  %7 = load i32***, i32**** %arrayidx75, align 4, !tbaa !14
+  %arrayidx76 = getelementptr inbounds i32**, i32*** %7, i32 %idxprom52
+  %8 = load i32**, i32*** %arrayidx76, align 4, !tbaa !14
+  %cond87.in671 = load i32*, i32** %8, align 4
+  %cond87672 = load i32, i32* %cond87.in671, align 4
+  %conv88673 = trunc i32 %cond87672 to i16
+  store i16 %conv88673, i16* @weight1, align 2, !tbaa !5
+  %cond105 = load i32, i32* undef, align 4
+  %conv106 = trunc i32 %cond105 to i16
+  store i16 %conv106, i16* @weight2, align 2, !tbaa !5
+  store i16 0, i16* @offsetBi, align 2, !tbaa !5
+  %storemerge655 = load i32, i32* bitcast (i32 (i16*, i32, i32, i32, i32, i32, i32, i32)** getelementptr inbounds ([3 x i32 (i16*, i32, i32, i32, i32, i32, i32, i32)*], [3 x i32 (i16*, i32, i32, i32, i32, i32, i32, i32)*]* @computeBiPred2, i32 0, i32 1) to i32*), align 4
+  store i32 %storemerge655, i32* bitcast (i32 (i16*, i32, i32, i32, i32, i32, i32, i32)** @computeBiPred to i32*), align 4, !tbaa !14
+  %9 = load i16, i16* %mv_x, align 2, !tbaa !5
+  %cmp270 = icmp sgt i32 undef, 1
+  %or.cond = and i1 %cmp270, false
+  br i1 %or.cond, label %land.lhs.true277, label %if.else289
+
+land.lhs.true277:                                 ; preds = %entry
+  %10 = load i16, i16* %mv_y, align 2, !tbaa !5
+  %conv278 = sext i16 %10 to i32
+  %add279 = add nsw i32 %conv278, 0
+  %cmp280 = icmp sgt i32 %add279, 1
+  %or.cond660 = and i1 %cmp280, undef
+  br i1 %or.cond660, label %if.end290, label %if.else289
+
+if.else289:                                       ; preds = %land.lhs.true277, %entry
+  br label %if.end290
+
+if.end290:                                        ; preds = %if.else289, %land.lhs.true277
+  %storemerge = phi i32 [ 1, %if.else289 ], [ 0, %land.lhs.true277 ]
+  store i32 %storemerge, i32* @bipred2_access_method, align 4, !tbaa !1
+  %cmp315698 = icmp slt i32 %0, %cond47
+  br i1 %cmp315698, label %for.body.lr.ph, label %if.end358
+
+for.body.lr.ph:                                   ; preds = %if.end290
+  %conv328 = sext i16 %pred_mv_y to i32
+  br label %for.body
+
+for.body:                                         ; preds = %for.inc, %for.body.lr.ph
+  %11 = phi i16 [ %9, %for.body.lr.ph ], [ %.pre, %for.inc ]
+  %min_mcost.addr.0701 = phi i32 [ %min_mcost, %for.body.lr.ph ], [ undef, %for.inc ]
+  %pos.0700 = phi i32 [ %0, %for.body.lr.ph ], [ undef, %for.inc ]
+  %best_pos.0699 = phi i32 [ 0, %for.body.lr.ph ], [ %best_pos.1, %for.inc ]
+  %conv317 = sext i16 %11 to i32
+  %add320 = add nsw i32 0, %conv317
+  %12 = load i16, i16* %mv_y, align 2, !tbaa !5
+  %conv321 = sext i16 %12 to i32
+  %add324 = add nsw i32 0, %conv321
+  %13 = load i32*, i32** @mvbits, align 4, !tbaa !14
+  %14 = load i32, i32* undef, align 4, !tbaa !1
+  %sub329 = sub nsw i32 %add324, %conv328
+  %arrayidx330 = getelementptr inbounds i32, i32* %13, i32 %sub329
+  %15 = load i32, i32* %arrayidx330, align 4, !tbaa !1
+  %add331 = add nsw i32 %15, %14
+  %mul = mul nsw i32 %add331, %2
+  %shr332 = ashr i32 %mul, 16
+  %cmp333 = icmp sgt i32 %min_mcost.addr.0701, %shr332
+  br i1 %cmp333, label %if.end336, label %for.inc
+
+if.end336:                                        ; preds = %for.body
+  ; CHECK:      jalr  $25
+  ; CHECK-NOT:  move  $ra, {{.*}}
+  ; CHECK:      j     $BB{{.*}}
+  %add337 = add nsw i32 %add320, %shl
+  %add338 = add nsw i32 %add324, 0
+  %call340 = tail call i32 undef(i16* %orig_pic, i32 signext undef, i32 signext
+                                 undef, i32 signext 0, i32 signext %add49,
+                                 i32 signext undef, i32 signext %add337,
+                                 i32 signext %add338) #1
+  %cmp342 = icmp slt i32 0, %min_mcost.addr.0701
+  %pos.0.best_pos.0 = select i1 %cmp342, i32 %pos.0700, i32 %best_pos.0699
+  br label %for.inc
+
+for.inc:                                          ; preds = %if.end336, %for.body
+  %best_pos.1 = phi i32 [ %best_pos.0699, %for.body ], [ %pos.0.best_pos.0, %if.end336 ]
+  %.pre = load i16, i16* %mv_x, align 2, !tbaa !5
+  br label %for.body
+
+if.end358:                                        ; preds = %if.end290
+  %.min_mcost.addr.0 = select i1 false, i32 2147483647, i32 %min_mcost
+  br i1 undef, label %for.body415.lr.ph, label %if.end461
+
+for.body415.lr.ph:                                ; preds = %if.end358
+  %16 = load i16, i16* %mv_y, align 2, !tbaa !5
+  %conv420 = sext i16 %16 to i32
+  %add423 = add nsw i32 0, %conv420
+  %cmp433 = icmp sgt i32 %.min_mcost.addr.0, 0
+  br i1 %cmp433, label %if.end436, label %if.end461
+
+if.end436:                                        ; preds = %for.body415.lr.ph
+  %add438 = add nsw i32 %add423, 0
+  %call440 = tail call i32 @foobar(i16* %orig_pic, i32 signext undef, i32 signext undef,
+                                 i32 signext 0, i32 signext %add49, i32 signext undef,
+                                 i32 signext undef, i32 signext %add438) #1
+  br label %if.end461
+
+if.end461:                                        ; preds = %if.end436, %for.body415.lr.ph, %if.end358
+  ret void
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="mips32r2" "target-features"="+mips32r2,+nooddspreg,+fpxx" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version 3.7.0 (trunk 236218) (llvm/trunk 236237)"}
+!1 = !{!2, !2, i64 0}
+!2 = !{!"int", !3, i64 0}
+!3 = !{!"omnipotent char", !4, i64 0}
+!4 = !{!"Simple C/C++ TBAA"}
+!5 = !{!6, !6, i64 0}
+!6 = !{!"short", !3, i64 0}
+!7 = !{!8, !9, i64 0}
+!8 = !{!"", !9, i64 0, !3, i64 4}
+!9 = !{!"any pointer", !3, i64 0}
+!10 = !{!11, !9, i64 6440}
+!11 = !{!"storable_picture", !3, i64 0, !2, i64 4, !2, i64 8, !2, i64 12, !2, i64 16, !2, i64 20, !3, i64 24, !3, i64 1608, !3, i64 3192, !3, i64 4776, !2, i64 6360, !2, i64 6364, !2, i64 6368, !2, i64 6372, !2, i64 6376, !2, i64 6380, !2, i64 6384, !2, i64 6388, !2, i64 6392, !2, i64 6396, !2, i64 6400, !2, i64 6404, !2, i64 6408, !2, i64 6412, !2, i64 6416, !2, i64 6420, !2, i64 6424, !2, i64 6428, !2, i64 6432, !9, i64 6436, !9, i64 6440, !9, i64 6444, !9, i64 6448, !9, i64 6452, !9, i64 6456, !9, i64 6460, !9, i64 6464, !9, i64 6468, !9, i64 6472, !9, i64 6476, !9, i64 6480, !9, i64 6484, !9, i64 6488, !9, i64 6492, !2, i64 6496, !2, i64 6500, !2, i64 6504, !2, i64 6508, !2, i64 6512, !2, i64 6516, !2, i64 6520}
+!12 = !{!11, !2, i64 6408}
+!13 = !{!11, !2, i64 6412}
+!14 = !{!9, !9, i64 0}