[CostModel] Model all extractvalues as free.

Summary:
As disscussed in https://reviews.llvm.org/D65148#1606412,
`extractvalue` don't actually generate any code,
so we should treat them as free.

Reviewers: craig.topper, RKSimon, jnspaulsson, greened, asb, t.p.northover, jmolloy, dmgreen

Reviewed By: jmolloy

Subscribers: javed.absar, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66098

llvm-svn: 370339

Author: LebedevRI

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

@@ -840,6 +840,9 @@ class TargetTransformInfoImplCRTPBase : public TargetTransformInfoImplBase {
     if (isa<PHINode>(U))
       return TTI::TCC_Free; // Model all PHI nodes as free.
 
+    if (isa<ExtractValueInst>(U))
+      return TTI::TCC_Free; // Model all ExtractValue nodes as free.
+
     // Static alloca doesn't generate target instructions.
     if (auto *A = dyn_cast<AllocaInst>(U))
       if (A->isStaticAlloca())

llvm/lib/Analysis/TargetTransformInfo.cpp

@@ -1286,6 +1286,8 @@ int TargetTransformInfo::getInstructionThroughput(const Instruction *I) const {
     return getVectorInstrCost(I->getOpcode(),
                                    IE->getType(), Idx);
   }
+  case Instruction::ExtractValue:
+    return 0; // Model all ExtractValue nodes as free.
   case Instruction::ShuffleVector: {
     const ShuffleVectorInst *Shuffle = cast<ShuffleVectorInst>(I);
     Type *Ty = Shuffle->getType();

llvm/test/Analysis/CostModel/AArch64/aggregates.ll

@@ -5,15 +5,15 @@
 
 define i32 @extract_first_i32({i32, i32} %agg) {
 ; THROUGHPUT-LABEL: 'extract_first_i32'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, i32 } %agg, 0
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i32 } %agg, 0
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 %r
 ;
 ; LATENCY-LABEL: 'extract_first_i32'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i32 } %agg, 0
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i32 } %agg, 0
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 %r
 ;
 ; CODESIZE-LABEL: 'extract_first_i32'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i32 } %agg, 0
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i32 } %agg, 0
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 %r
 ;
   %r = extractvalue {i32, i32} %agg, 0
@@ -22,15 +22,15 @@ define i32 @extract_first_i32({i32, i32} %agg) {
 
 define i32 @extract_second_i32({i32, i32} %agg) {
 ; THROUGHPUT-LABEL: 'extract_second_i32'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, i32 } %agg, 1
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i32 } %agg, 1
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 %r
 ;
 ; LATENCY-LABEL: 'extract_second_i32'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i32 } %agg, 1
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i32 } %agg, 1
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 %r
 ;
 ; CODESIZE-LABEL: 'extract_second_i32'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i32 } %agg, 1
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i32 } %agg, 1
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 %r
 ;
   %r = extractvalue {i32, i32} %agg, 1
@@ -39,15 +39,15 @@ define i32 @extract_second_i32({i32, i32} %agg) {
 
 define i32 @extract_i32({i32, i1} %agg) {
 ; THROUGHPUT-LABEL: 'extract_i32'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, i1 } %agg, 0
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i1 } %agg, 0
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 %r
 ;
 ; LATENCY-LABEL: 'extract_i32'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i1 } %agg, 0
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i1 } %agg, 0
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 %r
 ;
 ; CODESIZE-LABEL: 'extract_i32'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i1 } %agg, 0
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i1 } %agg, 0
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 %r
 ;
   %r = extractvalue {i32, i1} %agg, 0
@@ -56,15 +56,15 @@ define i32 @extract_i32({i32, i1} %agg) {
 
 define i1 @extract_i1({i32, i1} %agg) {
 ; THROUGHPUT-LABEL: 'extract_i1'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, i1 } %agg, 1
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i1 } %agg, 1
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i1 %r
 ;
 ; LATENCY-LABEL: 'extract_i1'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i1 } %agg, 1
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i1 } %agg, 1
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i1 %r
 ;
 ; CODESIZE-LABEL: 'extract_i1'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, i1 } %agg, 1
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, i1 } %agg, 1
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i1 %r
 ;
   %r = extractvalue {i32, i1} %agg, 1
@@ -73,15 +73,15 @@ define i1 @extract_i1({i32, i1} %agg) {
 
 define float @extract_float({i32, float} %agg) {
 ; THROUGHPUT-LABEL: 'extract_float'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, float } %agg, 1
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, float } %agg, 1
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret float %r
 ;
 ; LATENCY-LABEL: 'extract_float'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %r = extractvalue { i32, float } %agg, 1
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, float } %agg, 1
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret float %r
 ;
 ; CODESIZE-LABEL: 'extract_float'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, float } %agg, 1
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, float } %agg, 1
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret float %r
 ;
   %r = extractvalue {i32, float} %agg, 1
@@ -90,15 +90,15 @@ define float @extract_float({i32, float} %agg) {
 
 define [42 x i42] @extract_array({i32, [42 x i42]} %agg) {
 ; THROUGHPUT-LABEL: 'extract_array'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, [42 x i42] } %agg, 1
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, [42 x i42] } %agg, 1
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret [42 x i42] %r
 ;
 ; LATENCY-LABEL: 'extract_array'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, [42 x i42] } %agg, 1
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, [42 x i42] } %agg, 1
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret [42 x i42] %r
 ;
 ; CODESIZE-LABEL: 'extract_array'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, [42 x i42] } %agg, 1
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, [42 x i42] } %agg, 1
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret [42 x i42] %r
 ;
   %r = extractvalue {i32, [42 x i42]} %agg, 1
@@ -107,15 +107,15 @@ define [42 x i42] @extract_array({i32, [42 x i42]} %agg) {
 
 define <42 x i42> @extract_vector({i32, <42 x i42>} %agg) {
 ; THROUGHPUT-LABEL: 'extract_vector'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, <42 x i42> } %agg, 1
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, <42 x i42> } %agg, 1
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret <42 x i42> %r
 ;
 ; LATENCY-LABEL: 'extract_vector'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, <42 x i42> } %agg, 1
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, <42 x i42> } %agg, 1
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret <42 x i42> %r
 ;
 ; CODESIZE-LABEL: 'extract_vector'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, <42 x i42> } %agg, 1
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, <42 x i42> } %agg, 1
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret <42 x i42> %r
 ;
   %r = extractvalue {i32, <42 x i42>} %agg, 1
@@ -126,15 +126,15 @@ define <42 x i42> @extract_vector({i32, <42 x i42>} %agg) {
 
 define %T1 @extract_struct({i32, %T1} %agg) {
 ; THROUGHPUT-LABEL: 'extract_struct'
-; THROUGHPUT-NEXT:  Cost Model: Unknown cost for instruction: %r = extractvalue { i32, %T1 } %agg, 1
+; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, %T1 } %agg, 1
 ; THROUGHPUT-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret %T1 %r
 ;
 ; LATENCY-LABEL: 'extract_struct'
-; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, %T1 } %agg, 1
+; LATENCY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, %T1 } %agg, 1
 ; LATENCY-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret %T1 %r
 ;
 ; CODESIZE-LABEL: 'extract_struct'
-; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %r = extractvalue { i32, %T1 } %agg, 1
+; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %r = extractvalue { i32, %T1 } %agg, 1
 ; CODESIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret %T1 %r
 ;
   %r = extractvalue {i32, %T1} %agg, 1