Revert "Enable exp10 libcall on linux (#68736)"

This reverts commit 9848fa4.

Causes buildbot failures.

Author: nikic

llvm/lib/Analysis/TargetLibraryInfo.cpp

@@ -560,12 +560,16 @@ static void initialize(TargetLibraryInfoImpl &TLI, const Triple &T,
     break;
   case Triple::Linux:
     // exp10, exp10f, exp10l is available on Linux (GLIBC) but are extremely
-    // buggy prior to glibc version 2.18. As this version is so old, we
-    // don't really need to worry about using exp10 on Linux.
-    TLI.setAvailableWithName(LibFunc_exp10, "__exp10");
-    TLI.setAvailableWithName(LibFunc_exp10f, "__exp10f");
-    TLI.setAvailableWithName(LibFunc_exp10l, "__exp10l");
-    break;
+    // buggy prior to glibc version 2.18. Until this version is widely deployed
+    // or we have a reasonable detection strategy, we cannot use exp10 reliably
+    // on Linux.
+    //
+    // Fall through to disable all of them.
+    [[fallthrough]];
+  default:
+    TLI.setUnavailable(LibFunc_exp10);
+    TLI.setUnavailable(LibFunc_exp10f);
+    TLI.setUnavailable(LibFunc_exp10l);
   }
 
   // ffsl is available on at least Darwin, Mac OS X, iOS, FreeBSD, and
@@ -837,9 +841,6 @@ static void initialize(TargetLibraryInfoImpl &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc_strndup);
     TLI.setUnavailable(LibFunc_strnlen);
     TLI.setUnavailable(LibFunc_toascii);
-    TLI.setUnavailable(LibFunc_exp10);
-    TLI.setUnavailable(LibFunc_exp10f);
-    TLI.setUnavailable(LibFunc_exp10l);
   }
 
   // As currently implemented in clang, NVPTX code has no standard library to

llvm/test/Transforms/InstCombine/double-float-shrink-1.ll

@@ -224,20 +224,11 @@ define double @expm1_test2(float %f)   {
 ; exp10f() doesn't exist for this triple, so it doesn't shrink.
 
 define float @exp10_test1(float %f)   {
-; LINUX-LABEL: define float @exp10_test1(
-; LINUX-SAME: float [[F:%.*]]) {
-; LINUX-NEXT:    [[EXP10F:%.*]] = call fast float @__exp10f(float [[F]])
-; LINUX-NEXT:    ret float [[EXP10F]]
-;
-; MS64-LABEL: define float @exp10_test1(
-; MS64-SAME: float [[F:%.*]]) {
-; MS64-NEXT:    [[EXP10F:%.*]] = call fast float @exp10f(float [[F]])
-; MS64-NEXT:    ret float [[EXP10F]]
-;
-; MS32-LABEL: define float @exp10_test1(
-; MS32-SAME: float [[F:%.*]]) {
-; MS32-NEXT:    [[EXP10F:%.*]] = call fast float @exp10f(float [[F]])
-; MS32-NEXT:    ret float [[EXP10F]]
+; CHECK-LABEL: @exp10_test1(
+; CHECK-NEXT:    [[CONV:%.*]] = fpext float [[F:%.*]] to double
+; CHECK-NEXT:    [[CALL:%.*]] = call fast double @exp10(double [[CONV]])
+; CHECK-NEXT:    [[CONV1:%.*]] = fptrunc double [[CALL]] to float
+; CHECK-NEXT:    ret float [[CONV1]]
 ;
   %conv = fpext float %f to double
   %call = call fast double @exp10(double %conv)

llvm/test/Transforms/InstCombine/pow-1.ll

@@ -870,30 +870,10 @@ define float @test_simplify18(float %x) {
 ; CHECK-EXP10-NEXT:    [[__EXP10F:%.*]] = call float @__exp10f(float [[X]])
 ; CHECK-EXP10-NEXT:    ret float [[__EXP10F]]
 ;
-; VC32-LABEL: define float @test_simplify18(
-; VC32-SAME: float [[X:%.*]]) {
-; VC32-NEXT:    [[RETVAL:%.*]] = call float @powf(float 1.000000e+01, float [[X]])
-; VC32-NEXT:    ret float [[RETVAL]]
-;
-; VC51-LABEL: define float @test_simplify18(
-; VC51-SAME: float [[X:%.*]]) {
-; VC51-NEXT:    [[RETVAL:%.*]] = call float @powf(float 1.000000e+01, float [[X]])
-; VC51-NEXT:    ret float [[RETVAL]]
-;
-; VC64-LABEL: define float @test_simplify18(
-; VC64-SAME: float [[X:%.*]]) {
-; VC64-NEXT:    [[EXP10F:%.*]] = call float @exp10f(float [[X]])
-; VC64-NEXT:    ret float [[EXP10F]]
-;
-; VC83-LABEL: define float @test_simplify18(
-; VC83-SAME: float [[X:%.*]]) {
-; VC83-NEXT:    [[EXP10F:%.*]] = call float @exp10f(float [[X]])
-; VC83-NEXT:    ret float [[EXP10F]]
-;
-; NOLIB-LABEL: define float @test_simplify18(
-; NOLIB-SAME: float [[X:%.*]]) {
-; NOLIB-NEXT:    [[RETVAL:%.*]] = call float @powf(float 1.000000e+01, float [[X]])
-; NOLIB-NEXT:    ret float [[RETVAL]]
+; CHECK-NO-EXP10-LABEL: define float @test_simplify18(
+; CHECK-NO-EXP10-SAME: float [[X:%.*]]) {
+; CHECK-NO-EXP10-NEXT:    [[RETVAL:%.*]] = call float @powf(float 1.000000e+01, float [[X]])
+; CHECK-NO-EXP10-NEXT:    ret float [[RETVAL]]
 ;
   %retval = call float @powf(float 10.0, float %x)
   ret float %retval
@@ -905,28 +885,11 @@ define double @test_simplify19(double %x) {
 ; CHECK-EXP10-NEXT:    [[__EXP10:%.*]] = call double @__exp10(double [[X]])
 ; CHECK-EXP10-NEXT:    ret double [[__EXP10]]
 ;
-; VC32-LABEL: define double @test_simplify19(
-; VC32-SAME: double [[X:%.*]]) {
-; VC32-NEXT:    [[EXP10:%.*]] = call double @exp10(double [[X]])
-; VC32-NEXT:    ret double [[EXP10]]
-;
-; VC19-LABEL: define double @test_simplify19(
-; VC19-SAME: double [[X:%.*]]) {
-; VC19-NEXT:    [[EXP10:%.*]] = call double @exp10(double [[X]])
-; VC19-NEXT:    ret double [[EXP10]]
-;
-; VC64-LABEL: define double @test_simplify19(
-; VC64-SAME: double [[X:%.*]]) {
-; VC64-NEXT:    [[EXP10:%.*]] = call double @exp10(double [[X]])
-; VC64-NEXT:    ret double [[EXP10]]
-;
-; NOLIB-LABEL: define double @test_simplify19(
-; NOLIB-SAME: double [[X:%.*]]) {
-; NOLIB-NEXT:    [[RETVAL:%.*]] = call double @pow(double 1.000000e+01, double [[X]])
-; NOLIB-NEXT:    ret double [[RETVAL]]
+; CHECK-NO-EXP10-LABEL: define double @test_simplify19(
+; CHECK-NO-EXP10-SAME: double [[X:%.*]]) {
+; CHECK-NO-EXP10-NEXT:    [[RETVAL:%.*]] = call double @pow(double 1.000000e+01, double [[X]])
+; CHECK-NO-EXP10-NEXT:    ret double [[RETVAL]]
 ;
   %retval = call double @pow(double 10.0, double %x)
   ret double %retval
 }
-;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
-; CHECK-NO-EXP10: {{.*}}

llvm/test/Transforms/InstCombine/pow-exp.ll

@@ -136,11 +136,12 @@ define fp128 @powl_exp2l_not_fast(fp128 %x, fp128 %y) {
   ret fp128 %pow
 }
 
+; TODO: exp10() is not widely enabled by many targets yet.
+
 define float @powf_exp10f(float %x, float %y) {
-; CHECK-LABEL: define float @powf_exp10f(
-; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]]) {
-; CHECK-NEXT:    [[CALL:%.*]] = call fast float @exp10f(float [[X]]) #[[ATTR1:[0-9]+]]
-; CHECK-NEXT:    [[POW:%.*]] = call fast float @llvm.pow.f32(float [[CALL]], float [[Y]])
+; CHECK-LABEL: @powf_exp10f(
+; CHECK-NEXT:    [[CALL:%.*]] = call fast float @exp10f(float [[X:%.*]]) #[[ATTR1:[0-9]+]]
+; CHECK-NEXT:    [[POW:%.*]] = call fast float @llvm.pow.f32(float [[CALL]], float [[Y:%.*]])
 ; CHECK-NEXT:    ret float [[POW]]
 ;
   %call = call fast float @exp10f(float %x) nounwind readnone
@@ -149,10 +150,9 @@ define float @powf_exp10f(float %x, float %y) {
 }
 
 define double @pow_exp10(double %x, double %y) {
-; CHECK-LABEL: define double @pow_exp10(
-; CHECK-SAME: double [[X:%.*]], double [[Y:%.*]]) {
-; CHECK-NEXT:    [[CALL:%.*]] = call fast double @exp10(double [[X]]) #[[ATTR1]]
-; CHECK-NEXT:    [[POW:%.*]] = call fast double @llvm.pow.f64(double [[CALL]], double [[Y]])
+; CHECK-LABEL: @pow_exp10(
+; CHECK-NEXT:    [[CALL:%.*]] = call fast double @exp10(double [[X:%.*]]) #[[ATTR1]]
+; CHECK-NEXT:    [[POW:%.*]] = call fast double @llvm.pow.f64(double [[CALL]], double [[Y:%.*]])
 ; CHECK-NEXT:    ret double [[POW]]
 ;
   %call = call fast double @exp10(double %x) nounwind readnone
@@ -161,10 +161,9 @@ define double @pow_exp10(double %x, double %y) {
 }
 
 define fp128 @pow_exp10l(fp128 %x, fp128 %y) {
-; CHECK-LABEL: define fp128 @pow_exp10l(
-; CHECK-SAME: fp128 [[X:%.*]], fp128 [[Y:%.*]]) {
-; CHECK-NEXT:    [[CALL:%.*]] = call fast fp128 @exp10l(fp128 [[X]]) #[[ATTR1]]
-; CHECK-NEXT:    [[POW:%.*]] = call fast fp128 @llvm.pow.f128(fp128 [[CALL]], fp128 [[Y]])
+; CHECK-LABEL: @pow_exp10l(
+; CHECK-NEXT:    [[CALL:%.*]] = call fast fp128 @exp10l(fp128 [[X:%.*]]) #[[ATTR1]]
+; CHECK-NEXT:    [[POW:%.*]] = call fast fp128 @llvm.pow.f128(fp128 [[CALL]], fp128 [[Y:%.*]])
 ; CHECK-NEXT:    ret fp128 [[POW]]
 ;
   %call = call fast fp128 @exp10l(fp128 %x) nounwind readnone
@@ -256,10 +255,10 @@ define double @pow_ok_base3(double %e) {
 }
 
 define double @pow_ok_ten_base(double %e) {
-; CHECK-LABEL: define double @pow_ok_ten_base(
-; CHECK-SAME: double [[E:%.*]]) {
-; CHECK-NEXT:    [[EXP10:%.*]] = tail call nnan ninf afn double @exp10(double [[E]])
-; CHECK-NEXT:    ret double [[EXP10]]
+; CHECK-LABEL: @pow_ok_ten_base(
+; CHECK-NEXT:    [[MUL:%.*]] = fmul nnan ninf afn double [[E:%.*]], 0x400A934F{{.*}}
+; CHECK-NEXT:    [[EXP2:%.*]] = tail call nnan ninf afn double @exp2(double [[MUL]])
+; CHECK-NEXT:    ret double [[EXP2]]
 ;
   %call = tail call afn nnan ninf double @pow(double 1.000000e+01, double %e)
   ret double %call
@@ -306,10 +305,10 @@ define float @powf_ok_base3(float %e) {
 }
 
 define float @powf_ok_ten_base(float %e) {
-; CHECK-LABEL: define float @powf_ok_ten_base(
-; CHECK-SAME: float [[E:%.*]]) {
-; CHECK-NEXT:    [[EXP10F:%.*]] = tail call nnan ninf afn float @exp10f(float [[E]])
-; CHECK-NEXT:    ret float [[EXP10F]]
+; CHECK-LABEL: @powf_ok_ten_base(
+; CHECK-NEXT:    [[MUL:%.*]] = fmul nnan ninf afn float [[E:%.*]], 0x400A934{{.*}}
+; CHECK-NEXT:    [[EXP2F:%.*]] = tail call nnan ninf afn float @exp2f(float [[MUL]])
+; CHECK-NEXT:    ret float [[EXP2F]]
 ;
   %call = tail call afn nnan ninf float @powf(float 1.000000e+01, float %e)
   ret float %call