[TLI] Add basic support for nextafter/nexttoward libcalls (#166250)

sivakusayan · web-flow · commit e79528f7b82b · 2025-11-05T21:18:18.000Z
First patch for #74368. Constant folding will be added in a follow-up patch.
diff --git a/llvm/include/llvm/Analysis/TargetLibraryInfo.def b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
@@ -1951,6 +1951,36 @@ TLI_DEFINE_ENUM_INTERNAL(nearbyintl)
 TLI_DEFINE_STRING_INTERNAL("nearbyintl")
 TLI_DEFINE_SIG_INTERNAL(LDbl, LDbl)
 
+/// double nextafter(double x, double y);
+TLI_DEFINE_ENUM_INTERNAL(nextafter)
+TLI_DEFINE_STRING_INTERNAL("nextafter")
+TLI_DEFINE_SIG_INTERNAL(Dbl, Dbl, Dbl)
+
+/// float nextafterf(float x, float y);
+TLI_DEFINE_ENUM_INTERNAL(nextafterf)
+TLI_DEFINE_STRING_INTERNAL("nextafterf")
+TLI_DEFINE_SIG_INTERNAL(Flt, Flt, Flt)
+
+/// long double nextafterl(long double x, long double y);
+TLI_DEFINE_ENUM_INTERNAL(nextafterl)
+TLI_DEFINE_STRING_INTERNAL("nextafterl")
+TLI_DEFINE_SIG_INTERNAL(LDbl, LDbl, LDbl)
+
+/// double nexttoward(double x, long double y);
+TLI_DEFINE_ENUM_INTERNAL(nexttoward)
+TLI_DEFINE_STRING_INTERNAL("nexttoward")
+TLI_DEFINE_SIG_INTERNAL(Dbl, Dbl, LDbl)
+
+/// float nexttowardf(float x, long double y);
+TLI_DEFINE_ENUM_INTERNAL(nexttowardf)
+TLI_DEFINE_STRING_INTERNAL("nexttowardf")
+TLI_DEFINE_SIG_INTERNAL(Flt, Flt, LDbl)
+
+/// long double nexttowardl(long double x, long double y);
+TLI_DEFINE_ENUM_INTERNAL(nexttowardl)
+TLI_DEFINE_STRING_INTERNAL("nexttowardl")
+TLI_DEFINE_SIG_INTERNAL(LDbl, LDbl, LDbl)
+
 /// uint32_t ntohl(uint32_t netlong);
 TLI_DEFINE_ENUM_INTERNAL(ntohl)
 TLI_DEFINE_STRING_INTERNAL("ntohl")
diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -388,6 +388,10 @@ static void initializeLibCalls(TargetLibraryInfoImpl &TLI, const Triple &T,
         TLI.setAvailableWithName(LibFunc_logbf, "_logbf");
       else
         TLI.setUnavailable(LibFunc_logbf);
+      TLI.setUnavailable(LibFunc_nextafter);
+      TLI.setUnavailable(LibFunc_nextafterf);
+      TLI.setUnavailable(LibFunc_nexttoward);
+      TLI.setUnavailable(LibFunc_nexttowardf);
       TLI.setUnavailable(LibFunc_rint);
       TLI.setUnavailable(LibFunc_rintf);
       TLI.setUnavailable(LibFunc_round);
@@ -418,6 +422,8 @@ static void initializeLibCalls(TargetLibraryInfoImpl &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc_logbl);
     TLI.setUnavailable(LibFunc_ilogbl);
     TLI.setUnavailable(LibFunc_nearbyintl);
+    TLI.setUnavailable(LibFunc_nextafterl);
+    TLI.setUnavailable(LibFunc_nexttowardl);
     TLI.setUnavailable(LibFunc_rintl);
     TLI.setUnavailable(LibFunc_roundl);
     TLI.setUnavailable(LibFunc_scalblnl);
diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -1283,6 +1283,12 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
   case LibFunc_ilogbl:
   case LibFunc_logf:
   case LibFunc_logl:
+  case LibFunc_nextafter:
+  case LibFunc_nextafterf:
+  case LibFunc_nextafterl:
+  case LibFunc_nexttoward:
+  case LibFunc_nexttowardf:
+  case LibFunc_nexttowardl:
   case LibFunc_pow:
   case LibFunc_powf:
   case LibFunc_powl:
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -762,6 +762,24 @@ declare float @nearbyintf(float)
 ; CHECK: declare x86_fp80 @nearbyintl(x86_fp80) [[MEMNONE_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
 declare x86_fp80 @nearbyintl(x86_fp80)
 
+; CHECK: declare double @nextafter(double, double) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare double @nextafter(double, double)
+
+; CHECK: declare float @nextafterf(float, float) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare float @nextafterf(float, float)
+
+; CHECK: declare x86_fp80 @nextafterl(x86_fp80, x86_fp80) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare x86_fp80 @nextafterl(x86_fp80, x86_fp80)
+
+; CHECK: declare double @nexttoward(double, x86_fp80) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare double @nexttoward(double, x86_fp80)
+
+; CHECK: declare float @nexttowardf(float, x86_fp80) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare float @nexttowardf(float, x86_fp80)
+
+; CHECK: declare x86_fp80 @nexttowardl(x86_fp80, x86_fp80) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare x86_fp80 @nexttowardl(x86_fp80, x86_fp80)
+
 ; CHECK-LINUX: declare noundef i32 @open(ptr noundef readonly captures(none), i32 noundef, ...) [[NOFREE]]
 ; CHECK-OPEN: declare noundef i32 @open(ptr noundef readonly captures(none), i32 noundef, ...) [[NOFREE:#[0-9]+]]
 declare i32 @open(ptr, i32, ...)
diff --git a/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml b/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
@@ -34,7 +34,7 @@
 #
 # CHECK: << Total TLI yes SDK no:  18
 # CHECK: >> Total TLI no  SDK yes: 0
-# CHECK: == Total TLI yes SDK yes: 271
+# CHECK: == Total TLI yes SDK yes: 277
 #
 # WRONG_DETAIL: << TLI yes SDK no : '_ZdaPv' aka operator delete[](void*)
 # WRONG_DETAIL: >> TLI no  SDK yes: '_ZdaPvj' aka operator delete[](void*, unsigned int)
@@ -48,14 +48,14 @@
 # WRONG_DETAIL: << TLI yes SDK no : 'fminimum_numl'
 # WRONG_SUMMARY: << Total TLI yes SDK no:  19{{$}}
 # WRONG_SUMMARY: >> Total TLI no  SDK yes: 1{{$}}
-# WRONG_SUMMARY: == Total TLI yes SDK yes: 270
+# WRONG_SUMMARY: == Total TLI yes SDK yes: 276
 #
 ## The -COUNT suffix doesn't care if there are too many matches, so check
 ## the exact count first; the two directives should add up to that.
 ## Yes, this means additions to TLI will fail this test, but the argument
 ## to -COUNT can't be an expression.
-# AVAIL: TLI knows 524 symbols, 289 available
-# AVAIL-COUNT-289: {{^}} available
+# AVAIL: TLI knows 530 symbols, 295 available
+# AVAIL-COUNT-295: {{^}} available
 # AVAIL-NOT:       {{^}} available
 # UNAVAIL-COUNT-235: not available
 # UNAVAIL-NOT:       not available
@@ -778,6 +778,30 @@ DynamicSymbols:
     Type:            STT_FUNC
     Section:         .text
     Binding:         STB_GLOBAL
+  - Name:            nextafter
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            nextafterf
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            nextafterl
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            nexttoward
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            nexttowardf
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            nexttowardl
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
   - Name:            perror
     Type:            STT_FUNC
     Section:         .text
diff --git a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
@@ -277,6 +277,12 @@ TEST_F(TargetLibraryInfoTest, ValidProto) {
       "declare x86_fp80 @logbl(x86_fp80)\n"
       "declare float @logf(float)\n"
       "declare x86_fp80 @logl(x86_fp80)\n"
+      "declare double @nextafter(double, double)\n"
+      "declare float @nextafterf(float, float)\n"
+      "declare x86_fp80 @nextafterl(x86_fp80, x86_fp80)\n"
+      "declare double @nexttoward(double, x86_fp80)\n"
+      "declare float @nexttowardf(float, x86_fp80)\n"
+      "declare x86_fp80 @nexttowardl(x86_fp80, x86_fp80)\n"
       "declare i8* @malloc(i64)\n"
       "declare i8* @memccpy(i8*, i8*, i32, i64)\n"
       "declare i8* @memchr(i8*, i32, i64)\n"
