Revert "[CodeGenPrepare] Freeze condition when transforming select to…

… br" This reverts commit 10aa7ea.
llvm · Mar 16, 2020 · 4ffe3ac · 4ffe3ac
1 parent 4c90a52
commit 4ffe3ac
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Showing 4 changed files with 9 additions and 19 deletions.
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -6131,16 +6131,14 @@ bool CodeGenPrepare::optimizeSelectInst(SelectInst *SI) {
   // Into:
   //    start:
   //       %cmp = cmp uge i32 %a, %b
-  //       %cmp.frozen = freeze %cmp
-  //       br i1 %cmp.frozen, label %select.true, label %select.false
+  //       br i1 %cmp, label %select.true, label %select.false
   //    select.true:
   //       br label %select.end
   //    select.false:
   //       br label %select.end
   //    select.end:
   //       %sel = phi i32 [ %c, %select.true ], [ %d, %select.false ]
   //
-  // %cmp should be freezed, otherwise it may introduce undefined behavior.
   // In addition, we may sink instructions that produce %c or %d from
   // the entry block into the destination(s) of the new branch.
   // If the true or false blocks do not contain a sunken instruction, that
@@ -6219,9 +6217,7 @@ bool CodeGenPrepare::optimizeSelectInst(SelectInst *SI) {
     TT = TrueBlock;
     FT = FalseBlock;
   }
-  IRBuilder<> IB(SI);
-  auto CondFr = IB.CreateFreeze(SI->getCondition(), SI->getName() + ".frozen");
-  IB.CreateCondBr(CondFr, TT, FT, SI);
+  IRBuilder<>(SI).CreateCondBr(SI->getCondition(), TT, FT, SI);
 
   SmallPtrSet<const Instruction *, 2> INS;
   INS.insert(ASI.begin(), ASI.end());

diff --git a/llvm/test/CodeGen/ARM/2012-08-30-select.ll b/llvm/test/CodeGen/ARM/2012-08-30-select.ll
@@ -2,9 +2,9 @@
 ; rdar://12201387
 
 ;CHECK-LABEL: select_s_v_v:
-;CHECK: vmov.i32
 ;CHECK: vmov
 ;CHECK-NEXT: vmov
+;CHECK: vmov.i32
 ;CHECK: bx
 define <16 x i8> @select_s_v_v(<16 x i8> %vec, i32 %avail) {
 entry:

diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/optimizeSelect-DT.ll b/llvm/test/Transforms/CodeGenPrepare/X86/optimizeSelect-DT.ll
@@ -7,8 +7,7 @@ target triple = "x86_64-unknown-linux-gnu"
 define i1 @PR41004(i32 %x, i32 %y, i32 %t1) {
 ; CHECK-LABEL: @PR41004(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[MUL_FR:%.*]] = freeze i32 [[Y:%.*]]
-; CHECK-NEXT:    [[T0:%.*]] = icmp eq i32 [[MUL_FR]], 1
+; CHECK-NEXT:    [[T0:%.*]] = icmp eq i32 [[Y:%.*]], 1
 ; CHECK-NEXT:    br i1 [[T0]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_END:%.*]]
 ; CHECK:       select.true.sink:
 ; CHECK-NEXT:    [[REM:%.*]] = srem i32 [[X:%.*]], 2

diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/select.ll b/llvm/test/Transforms/CodeGenPrepare/X86/select.ll
@@ -27,8 +27,7 @@ entry:
 define float @fdiv_true_sink(float %a, float %b) {
 ; CHECK-LABEL: @fdiv_true_sink(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[SEL_FR:%.*]] = freeze float [[A:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 1.000000e+00
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 1.000000e+00
 ; CHECK-NEXT:    br i1 [[CMP]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_END:%.*]]
 ; CHECK:       select.true.sink:
 ; CHECK-NEXT:    [[DIV:%.*]] = fdiv float [[A]], [[B:%.*]]
@@ -39,8 +38,7 @@ define float @fdiv_true_sink(float %a, float %b) {
 ;
 ; DEBUG-LABEL: @fdiv_true_sink(
 ; DEBUG-NEXT:  entry:
-; DEBUG-NEXT:    [[SEL_FR:%.*]] = freeze float [[A:%.*]]
-; DEBUG-NEXT:    [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 1.000000e+00, !dbg !24
+; DEBUG-NEXT:    [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 1.000000e+00
 ; DEBUG-NEXT:    call void @llvm.dbg.value(metadata i1 [[CMP]]
 ; DEBUG-NEXT:    br i1 [[CMP]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_END:%.*]], !dbg
 ; DEBUG:       select.true.sink:
@@ -62,8 +60,7 @@ entry:
 define float @fdiv_false_sink(float %a, float %b) {
 ; CHECK-LABEL: @fdiv_false_sink(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[SEL_FR:%.*]] = freeze float [[A:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 3.000000e+00
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 3.000000e+00
 ; CHECK-NEXT:    br i1 [[CMP]], label [[SELECT_END:%.*]], label [[SELECT_FALSE_SINK:%.*]]
 ; CHECK:       select.false.sink:
 ; CHECK-NEXT:    [[DIV:%.*]] = fdiv float [[A]], [[B:%.*]]
@@ -74,8 +71,7 @@ define float @fdiv_false_sink(float %a, float %b) {
 ;
 ; DEBUG-LABEL: @fdiv_false_sink(
 ; DEBUG-NEXT:  entry:
-; DEBUG-NEXT:    [[SEL_FR:%.*]] = freeze float [[A:%.*]]
-; DEBUG-NEXT:    [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 3.000000e+00, !dbg !33
+; DEBUG-NEXT:    [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 3.000000e+00
 ; DEBUG-NEXT:    call void @llvm.dbg.value(metadata i1 [[CMP]]
 ; DEBUG-NEXT:    br i1 [[CMP]], label [[SELECT_END:%.*]], label [[SELECT_FALSE_SINK:%.*]], !dbg
 ; DEBUG:       select.false.sink:
@@ -97,8 +93,7 @@ entry:
 define float @fdiv_both_sink(float %a, float %b) {
 ; CHECK-LABEL: @fdiv_both_sink(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[SEL_FR:%.*]] = freeze float [[A:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt float [[SEL_FR]], 5.000000e+00
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt float [[A:%.*]], 5.000000e+00
 ; CHECK-NEXT:    br i1 [[CMP]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_FALSE_SINK:%.*]]
 ; CHECK:       select.true.sink:
 ; CHECK-NEXT:    [[DIV1:%.*]] = fdiv float [[A]], [[B:%.*]]