[llvm] r255562 - Revert "Don't create unnecessary PHIs"

Reid Kleckner via llvm-commits llvm-commits at lists.llvm.org
Mon Dec 14 14:36:57 PST 2015


Author: rnk
Date: Mon Dec 14 16:36:57 2015
New Revision: 255562

URL: http://llvm.org/viewvc/llvm-project?rev=255562&view=rev
Log:
Revert "Don't create unnecessary PHIs"

This reverts commit r255489.

It causes test failures in Chromium and does not appear to respect the
AlternativeV parameter.

Removed:
    llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll
Modified:
    llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
    llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores.ll

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=255562&r1=255561&r2=255562&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Mon Dec 14 16:36:57 2015
@@ -2385,11 +2385,6 @@ static Value *ensureValueAvailableInSucc
   // If AlternativeV is not nullptr, we care about both incoming values in PHI.
   // PHI must be exactly: phi <ty> [ %BB, %V ], [ %OtherBB, %AlternativeV]
   // where OtherBB is the single other predecessor of BB's only successor.
-
-  // If V is not an instruction defined in BB, just return it.
-  if (!isa<Instruction>(V) || cast<Instruction>(V)->getParent() != BB)
-    return V;
-
   PHINode *PHI = nullptr;
   BasicBlock *Succ = BB->getSingleSuccessor();
   

Removed: llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll?rev=255561&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll (removed)
@@ -1,198 +0,0 @@
-; RUN: opt -S < %s -simplifycfg -simplifycfg-merge-cond-stores=true -simplifycfg-merge-cond-stores-aggressively=false -phi-node-folding-threshold=2 | FileCheck %s
-
-target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
-target triple = "armv7--linux-gnueabihf"
-
-; This is a bit reversal that has been run through the early optimizer (-mem2reg -gvn -instcombine).
-; There should be no additional PHIs created at all. The store should be on its own in a predicated
-; block and there should be no PHIs.
-
-; CHECK-LABEL: @f
-; CHECK-NOT: phi
-; CHECK: br i1 {{.*}}, label %[[L:.*]], label %[[R:.*]]
-; CHECK: [[L]] ; preds = 
-; CHECK-NEXT: store
-; CHECK-NEXT: br label %[[R]]
-; CHECK: [[R]] ; preds = 
-; CHECK-NEXT: ret i32 0
-
-define i32 @f(i32* %b) {
-entry:
-  %0 = load i32, i32* %b, align 4
-  %and = and i32 %0, 1
-  %tobool = icmp eq i32 %and, 0
-  br i1 %tobool, label %if.end, label %if.then
-
-if.then:                                          ; preds = %entry
-  %or = or i32 %0, -2147483648
-  store i32 %or, i32* %b, align 4
-  br label %if.end
-
-if.end:                                           ; preds = %entry, %if.then
-  %1 = phi i32 [ %0, %entry ], [ %or, %if.then ]
-  %and1 = and i32 %1, 2
-  %tobool2 = icmp eq i32 %and1, 0
-  br i1 %tobool2, label %if.end5, label %if.then3
-
-if.then3:                                         ; preds = %if.end
-  %or4 = or i32 %1, 1073741824
-  store i32 %or4, i32* %b, align 4
-  br label %if.end5
-
-if.end5:                                          ; preds = %if.end, %if.then3
-  %2 = phi i32 [ %1, %if.end ], [ %or4, %if.then3 ]
-  %and6 = and i32 %2, 4
-  %tobool7 = icmp eq i32 %and6, 0
-  br i1 %tobool7, label %if.end10, label %if.then8
-
-if.then8:                                         ; preds = %if.end5
-  %or9 = or i32 %2, 536870912
-  store i32 %or9, i32* %b, align 4
-  br label %if.end10
-
-if.end10:                                         ; preds = %if.end5, %if.then8
-  %3 = phi i32 [ %2, %if.end5 ], [ %or9, %if.then8 ]
-  %and11 = and i32 %3, 8
-  %tobool12 = icmp eq i32 %and11, 0
-  br i1 %tobool12, label %if.end15, label %if.then13
-
-if.then13:                                        ; preds = %if.end10
-  %or14 = or i32 %3, 268435456
-  store i32 %or14, i32* %b, align 4
-  br label %if.end15
-
-if.end15:                                         ; preds = %if.end10, %if.then13
-  %4 = phi i32 [ %3, %if.end10 ], [ %or14, %if.then13 ]
-  %and16 = and i32 %4, 16
-  %tobool17 = icmp eq i32 %and16, 0
-  br i1 %tobool17, label %if.end20, label %if.then18
-
-if.then18:                                        ; preds = %if.end15
-  %or19 = or i32 %4, 134217728
-  store i32 %or19, i32* %b, align 4
-  br label %if.end20
-
-if.end20:                                         ; preds = %if.end15, %if.then18
-  %5 = phi i32 [ %4, %if.end15 ], [ %or19, %if.then18 ]
-  %and21 = and i32 %5, 32
-  %tobool22 = icmp eq i32 %and21, 0
-  br i1 %tobool22, label %if.end25, label %if.then23
-
-if.then23:                                        ; preds = %if.end20
-  %or24 = or i32 %5, 67108864
-  store i32 %or24, i32* %b, align 4
-  br label %if.end25
-
-if.end25:                                         ; preds = %if.end20, %if.then23
-  %6 = phi i32 [ %5, %if.end20 ], [ %or24, %if.then23 ]
-  %and26 = and i32 %6, 64
-  %tobool27 = icmp eq i32 %and26, 0
-  br i1 %tobool27, label %if.end30, label %if.then28
-
-if.then28:                                        ; preds = %if.end25
-  %or29 = or i32 %6, 33554432
-  store i32 %or29, i32* %b, align 4
-  br label %if.end30
-
-if.end30:                                         ; preds = %if.end25, %if.then28
-  %7 = phi i32 [ %6, %if.end25 ], [ %or29, %if.then28 ]
-  %and31 = and i32 %7, 256
-  %tobool32 = icmp eq i32 %and31, 0
-  br i1 %tobool32, label %if.end35, label %if.then33
-
-if.then33:                                        ; preds = %if.end30
-  %or34 = or i32 %7, 8388608
-  store i32 %or34, i32* %b, align 4
-  br label %if.end35
-
-if.end35:                                         ; preds = %if.end30, %if.then33
-  %8 = phi i32 [ %7, %if.end30 ], [ %or34, %if.then33 ]
-  %and36 = and i32 %8, 512
-  %tobool37 = icmp eq i32 %and36, 0
-  br i1 %tobool37, label %if.end40, label %if.then38
-
-if.then38:                                        ; preds = %if.end35
-  %or39 = or i32 %8, 4194304
-  store i32 %or39, i32* %b, align 4
-  br label %if.end40
-
-if.end40:                                         ; preds = %if.end35, %if.then38
-  %9 = phi i32 [ %8, %if.end35 ], [ %or39, %if.then38 ]
-  %and41 = and i32 %9, 1024
-  %tobool42 = icmp eq i32 %and41, 0
-  br i1 %tobool42, label %if.end45, label %if.then43
-
-if.then43:                                        ; preds = %if.end40
-  %or44 = or i32 %9, 2097152
-  store i32 %or44, i32* %b, align 4
-  br label %if.end45
-
-if.end45:                                         ; preds = %if.end40, %if.then43
-  %10 = phi i32 [ %9, %if.end40 ], [ %or44, %if.then43 ]
-  %and46 = and i32 %10, 2048
-  %tobool47 = icmp eq i32 %and46, 0
-  br i1 %tobool47, label %if.end50, label %if.then48
-
-if.then48:                                        ; preds = %if.end45
-  %or49 = or i32 %10, 1048576
-  store i32 %or49, i32* %b, align 4
-  br label %if.end50
-
-if.end50:                                         ; preds = %if.end45, %if.then48
-  %11 = phi i32 [ %10, %if.end45 ], [ %or49, %if.then48 ]
-  %and51 = and i32 %11, 4096
-  %tobool52 = icmp eq i32 %and51, 0
-  br i1 %tobool52, label %if.end55, label %if.then53
-
-if.then53:                                        ; preds = %if.end50
-  %or54 = or i32 %11, 524288
-  store i32 %or54, i32* %b, align 4
-  br label %if.end55
-
-if.end55:                                         ; preds = %if.end50, %if.then53
-  %12 = phi i32 [ %11, %if.end50 ], [ %or54, %if.then53 ]
-  %and56 = and i32 %12, 8192
-  %tobool57 = icmp eq i32 %and56, 0
-  br i1 %tobool57, label %if.end60, label %if.then58
-
-if.then58:                                        ; preds = %if.end55
-  %or59 = or i32 %12, 262144
-  store i32 %or59, i32* %b, align 4
-  br label %if.end60
-
-if.end60:                                         ; preds = %if.end55, %if.then58
-  %13 = phi i32 [ %12, %if.end55 ], [ %or59, %if.then58 ]
-  %and61 = and i32 %13, 16384
-  %tobool62 = icmp eq i32 %and61, 0
-  br i1 %tobool62, label %if.end65, label %if.then63
-
-if.then63:                                        ; preds = %if.end60
-  %or64 = or i32 %13, 131072
-  store i32 %or64, i32* %b, align 4
-  br label %if.end65
-
-if.end65:                                         ; preds = %if.end60, %if.then63
-  %14 = phi i32 [ %13, %if.end60 ], [ %or64, %if.then63 ]
-  %and66 = and i32 %14, 32768
-  %tobool67 = icmp eq i32 %and66, 0
-  br i1 %tobool67, label %if.end70, label %if.then68
-
-if.then68:                                        ; preds = %if.end65
-  %or69 = or i32 %14, 65536
-  store i32 %or69, i32* %b, align 4
-  br label %if.end70
-
-if.end70:                                         ; preds = %if.end65, %if.then68
-  %15 = phi i32 [ %14, %if.end65 ], [ %or69, %if.then68 ]
-  %and71 = and i32 %15, 128
-  %tobool72 = icmp eq i32 %and71, 0
-  br i1 %tobool72, label %if.end75, label %if.then73
-
-if.then73:                                        ; preds = %if.end70
-  %or74 = or i32 %15, 16777216
-  store i32 %or74, i32* %b, align 4
-  br label %if.end75
-
-if.end75:                                         ; preds = %if.end70, %if.then73
-  ret i32 0
-}

Modified: llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores.ll?rev=255562&r1=255561&r2=255562&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/merge-cond-stores.ll Mon Dec 14 16:36:57 2015
@@ -2,8 +2,10 @@
 
 ; CHECK-LABEL: @test_simple
 ; This test should succeed and end up if-converted.
-; CHECK: %[[A:.*]] = or i32 %a, %b
-; CHECK-NEXT: %[[x:.*]] = icmp eq i32 %[[A]], 0
+; CHECK: icmp eq i32 %b, 0
+; CHECK-NEXT: icmp ne i32 %a, 0
+; CHECK-NEXT: xor i1 %x2, true
+; CHECK-NEXT: %[[x:.*]] = or i1 %{{.*}}, %{{.*}}
 ; CHECK-NEXT: br i1 %[[x]]
 ; CHECK: store
 ; CHECK-NOT: store




More information about the llvm-commits mailing list