InstSimplify: Handle exp10(log10(x)) -> x

Copy from exp/exp2 case.

https://reviews.llvm.org/D157894

Author: arsenm

llvm/lib/Analysis/InstructionSimplify.cpp

@@ -6154,6 +6154,12 @@ static Value *simplifyUnaryIntrinsic(Function *F, Value *Op0,
         match(Op0, m_Intrinsic<Intrinsic::log2>(m_Value(X))))
       return X;
     break;
+  case Intrinsic::exp10:
+    // exp10(log10(x)) -> x
+    if (Q.CxtI->hasAllowReassoc() &&
+        match(Op0, m_Intrinsic<Intrinsic::log10>(m_Value(X))))
+      return X;
+    break;
   case Intrinsic::log:
     // log(exp(x)) -> x
     if (Q.CxtI->hasAllowReassoc() &&

llvm/test/Transforms/InstSimplify/log-exp-intrinsic.ll

@@ -240,9 +240,7 @@ define double @log10_exp10_log10_exp10_reassoc(double %a) {
 
 define double @exp10_reassoc_log10_strict(double %a) {
 ; CHECK-LABEL: @exp10_reassoc_log10_strict(
-; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.log10.f64(double [[A:%.*]])
-; CHECK-NEXT:    [[TMP2:%.*]] = call reassoc double @llvm.exp10.f64(double [[TMP1]])
-; CHECK-NEXT:    ret double [[TMP2]]
+; CHECK-NEXT:    ret double [[A:%.*]]
 ;
   %1 = call double @llvm.log10.f64(double %a)
   %2 = call reassoc double @llvm.exp10.f64(double %1)
@@ -277,11 +275,7 @@ define double @exp10_log10_exp10_log10(double %a) {
 
 define double @exp10_log10_exp10_log10_reassoc(double %a) {
 ; CHECK-LABEL: @exp10_log10_exp10_log10_reassoc(
-; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.log10.f64(double [[A:%.*]])
-; CHECK-NEXT:    [[TMP2:%.*]] = call reassoc double @llvm.exp10.f64(double [[TMP1]])
-; CHECK-NEXT:    [[TMP3:%.*]] = call double @llvm.log10.f64(double [[TMP2]])
-; CHECK-NEXT:    [[TMP4:%.*]] = call reassoc double @llvm.exp10.f64(double [[TMP3]])
-; CHECK-NEXT:    ret double [[TMP4]]
+; CHECK-NEXT:    ret double [[A:%.*]]
 ;
   %1 = call double @llvm.log10.f64(double %a)
   %2 = call reassoc double @llvm.exp10.f64(double %1)