[llvm] r301950 - SpeculativeExecution: Stop using whitelist for costs

Matt Arsenault via llvm-commits llvm-commits at lists.llvm.org
Tue May 2 11:02:18 PDT 2017


Author: arsenm
Date: Tue May  2 13:02:18 2017
New Revision: 301950

URL: http://llvm.org/viewvc/llvm-project?rev=301950&view=rev
Log:
SpeculativeExecution: Stop using whitelist for costs

Just let TTI's cost do this instead of arbitrarily restricting
this.

Added:
    llvm/trunk/test/Transforms/SpeculativeExecution/spec-other.ll
    llvm/trunk/test/Transforms/SpeculativeExecution/spec-vector.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp?rev=301950&r1=301949&r2=301950&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp Tue May  2 13:02:18 2017
@@ -208,47 +208,6 @@ bool SpeculativeExecutionPass::runOnBasi
   return false;
 }
 
-static unsigned ComputeSpeculationCost(const Instruction *I,
-                                       const TargetTransformInfo &TTI) {
-  switch (Operator::getOpcode(I)) {
-    case Instruction::GetElementPtr:
-    case Instruction::Add:
-    case Instruction::Mul:
-    case Instruction::And:
-    case Instruction::Or:
-    case Instruction::Select:
-    case Instruction::Shl:
-    case Instruction::Sub:
-    case Instruction::LShr:
-    case Instruction::AShr:
-    case Instruction::Xor:
-    case Instruction::ZExt:
-    case Instruction::SExt:
-    case Instruction::Call:
-    case Instruction::BitCast:
-    case Instruction::PtrToInt:
-    case Instruction::IntToPtr:
-    case Instruction::AddrSpaceCast:
-    case Instruction::FPToUI:
-    case Instruction::FPToSI:
-    case Instruction::UIToFP:
-    case Instruction::SIToFP:
-    case Instruction::FPExt:
-    case Instruction::FPTrunc:
-    case Instruction::FAdd:
-    case Instruction::FSub:
-    case Instruction::FMul:
-    case Instruction::FDiv:
-    case Instruction::FRem:
-    case Instruction::ICmp:
-    case Instruction::FCmp:
-      return TTI.getUserCost(I);
-
-    default:
-      return UINT_MAX; // Disallow anything not whitelisted.
-  }
-}
-
 bool SpeculativeExecutionPass::considerHoistingFromTo(
     BasicBlock &FromBlock, BasicBlock &ToBlock) {
   SmallSet<const Instruction *, 8> NotHoisted;
@@ -264,7 +223,7 @@ bool SpeculativeExecutionPass::considerH
 
   unsigned TotalSpeculationCost = 0;
   for (auto& I : FromBlock) {
-    const unsigned Cost = ComputeSpeculationCost(&I, *TTI);
+    const unsigned Cost = TTI->getUserCost(&I);
     if (Cost != UINT_MAX && isSafeToSpeculativelyExecute(&I) &&
         AllPrecedingUsesFromBlockHoisted(&I)) {
       TotalSpeculationCost += Cost;

Added: llvm/trunk/test/Transforms/SpeculativeExecution/spec-other.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SpeculativeExecution/spec-other.ll?rev=301950&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SpeculativeExecution/spec-other.ll (added)
+++ llvm/trunk/test/Transforms/SpeculativeExecution/spec-other.ll Tue May  2 13:02:18 2017
@@ -0,0 +1,32 @@
+; RUN: opt < %s -S -speculative-execution \
+; RUN:   -spec-exec-max-speculation-cost 4 -spec-exec-max-not-hoisted 3 \
+; RUN:   | FileCheck %s
+
+; CHECK-LABEL: @ifThen_extractvalue(
+; CHECK: extractvalue
+; CHECK: br i1 true
+define void @ifThen_extractvalue() {
+  br i1 true, label %a, label %b
+
+a:
+  %x = extractvalue { i32, i32 } undef, 0
+  br label %b
+
+b:
+  ret void
+}
+
+; CHECK-LABEL: @ifThen_insertvalue(
+; CHECK: insertvalue
+; CHECK: br i1 true
+define void @ifThen_insertvalue() {
+  br i1 true, label %a, label %b
+
+a:
+  %x = insertvalue { i32, i32 } undef, i32 undef, 0
+  br label %b
+
+b:
+  ret void
+}
+

Added: llvm/trunk/test/Transforms/SpeculativeExecution/spec-vector.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SpeculativeExecution/spec-vector.ll?rev=301950&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SpeculativeExecution/spec-vector.ll (added)
+++ llvm/trunk/test/Transforms/SpeculativeExecution/spec-vector.ll Tue May  2 13:02:18 2017
@@ -0,0 +1,73 @@
+; RUN: opt < %s -S -speculative-execution \
+; RUN:   -spec-exec-max-speculation-cost 4 -spec-exec-max-not-hoisted 3 \
+; RUN:   | FileCheck %s
+
+; CHECK-LABEL: @ifThen_extractelement_constindex(
+; CHECK: extractelement
+; CHECK: br i1 true
+define void @ifThen_extractelement_constindex() {
+  br i1 true, label %a, label %b
+
+a:
+  %x = extractelement <4 x i32> undef, i32 0
+  br label %b
+
+b:
+  ret void
+}
+
+; CHECK-LABEL: @ifThen_extractelement_varindex(
+; CHECK: extractelement
+; CHECK: br i1 true
+define void @ifThen_extractelement_varindex(i32 %idx) {
+  br i1 true, label %a, label %b
+
+a:
+  %x = extractelement <4 x i32> undef, i32 %idx
+  br label %b
+
+b:
+  ret void
+}
+
+; CHECK-LABEL: @ifThen_insertelement_constindex(
+; CHECK: insertelement
+; CHECK: br i1 true
+define void @ifThen_insertelement_constindex() {
+  br i1 true, label %a, label %b
+
+a:
+  %x = insertelement <4 x i32> undef, i32 undef, i32 0
+  br label %b
+
+b:
+  ret void
+}
+
+; CHECK-LABEL: @ifThen_insertelement_varindex(
+; CHECK: insertelement
+; CHECK: br i1 true
+define void @ifThen_insertelement_varindex(i32 %idx) {
+  br i1 true, label %a, label %b
+
+a:
+  %x = insertelement <4 x i32> undef, i32 undef, i32 %idx
+  br label %b
+
+b:
+  ret void
+}
+
+; CHECK-LABEL: @ifThen_shufflevector(
+; CHECK: shufflevector
+; CHECK: br i1 true
+define void @ifThen_shufflevector() {
+  br i1 true, label %a, label %b
+
+a:
+  %x = shufflevector <4 x i32> undef, <4 x i32> undef, <4 x i32> undef
+  br label %b
+
+b:
+  ret void
+}




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