[LLVM] Add constant folding for llrint, llrintf, llrintl #154799

pratheekhassan21 · 2025-08-21T17:11:43Z

Fixes issue :#113914

github-actions · 2025-08-21T17:17:07Z

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llvmbot · 2025-08-21T17:17:40Z

@llvm/pr-subscribers-llvm-transforms

@llvm/pr-subscribers-llvm-analysis

Author: None (pratheekhassan21)

Changes

Fixes issue :#113914

Full diff: https://github.com/llvm/llvm-project/pull/154799.diff

11 Files Affected:

(modified) llvm/include/llvm/Analysis/TargetLibraryInfo.def (+19)
(modified) llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h (+1)
(modified) llvm/lib/Analysis/TargetLibraryInfo.cpp (+2)
(modified) llvm/lib/Transforms/Utils/BuildLibCalls.cpp (+7)
(modified) llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp (+27)
(modified) llvm/test/Transforms/InferFunctionAttrs/annotate.ll (+10)
(added) llvm/test/Transforms/InstCombine/llrint_fold.ll (+87)
(added) llvm/test/Transforms/InstCombine/llrintf_fold.ll (+33)
(added) llvm/test/Transforms/InstCombine/llrintl_fp80.ll (+65)
(modified) llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml (+20-4)
(modified) llvm/unittests/Analysis/TargetLibraryInfoTest.cpp (+3)

diff --git a/llvm/include/llvm/Analysis/TargetLibraryInfo.def b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
index db566b8ee610e..c9529b64ad77d 100644
--- a/llvm/include/llvm/Analysis/TargetLibraryInfo.def
+++ b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
@@ -2117,6 +2117,25 @@ TLI_DEFINE_ENUM_INTERNAL(remquol)
 TLI_DEFINE_STRING_INTERNAL("remquol")
 TLI_DEFINE_SIG_INTERNAL(LDbl, LDbl, LDbl, Ptr)
 
+
+//long long llrint ( double num );
+TLI_DEFINE_ENUM_INTERNAL(llrint)
+TLI_DEFINE_STRING_INTERNAL("llrint")
+TLI_DEFINE_SIG_INTERNAL(LLong,Dbl)
+
+
+//long long llrintf( float arg );
+TLI_DEFINE_ENUM_INTERNAL(llrintf)
+TLI_DEFINE_STRING_INTERNAL("llrintf")
+TLI_DEFINE_SIG_INTERNAL(LLong,Flt)
+
+//long long llrintl( long double arg );
+TLI_DEFINE_ENUM_INTERNAL(llrintl)
+TLI_DEFINE_STRING_INTERNAL("llrintl")
+TLI_DEFINE_SIG_INTERNAL(LLong,LDbl)
+
+
+
 /// double fdim(double x, double y);
 TLI_DEFINE_ENUM_INTERNAL(fdim)
 TLI_DEFINE_STRING_INTERNAL("fdim")
diff --git a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
index 128502b99d9a3..c4b04acf33daa 100644
--- a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
+++ b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
@@ -212,6 +212,7 @@ class LibCallSimplifier {
   Value *optimizeTrigInversionPairs(CallInst *CI, IRBuilderBase &B);
   Value *optimizeSymmetric(CallInst *CI, LibFunc Func, IRBuilderBase &B);
   Value *optimizeRemquo(CallInst *CI, IRBuilderBase &B);
+  Value *optimizellrint(CallInst *CI,IRBuilderBase &B);
   Value *optimizeFdim(CallInst *CI, IRBuilderBase &B);
   // Wrapper for all floating point library call optimizations
   Value *optimizeFloatingPointLibCall(CallInst *CI, LibFunc Func,
diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
index e2fd2aa13cce7..d871e4194ac55 100644
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -307,6 +307,7 @@ static void initializeLibCalls(TargetLibraryInfoImpl &TLI, const Triple &T,
       TLI.setUnavailable(LibFunc_powf);
       TLI.setUnavailable(LibFunc_remainderf);
       TLI.setUnavailable(LibFunc_remquof);
+      TLI.setUnavailable(LibFunc_llrintf);
       TLI.setUnavailable(LibFunc_fdimf);
       TLI.setUnavailable(LibFunc_sinf);
       TLI.setUnavailable(LibFunc_sinhf);
@@ -340,6 +341,7 @@ static void initializeLibCalls(TargetLibraryInfoImpl &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc_powl);
     TLI.setUnavailable(LibFunc_remainderl);
     TLI.setUnavailable(LibFunc_remquol);
+    TLI.setUnavailable(LibFunc_llrintl);
     TLI.setUnavailable(LibFunc_fdiml);
     TLI.setUnavailable(LibFunc_sinl);
     TLI.setUnavailable(LibFunc_sinhl);
diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index a5f6047b0b7ae..68887f5becdf0 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -1383,6 +1383,13 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
     Changed |= setWillReturn(F);
     Changed |= setOnlyWritesArgMemOrErrnoMem(F);
     break;
+  case LibFunc_llrintf:
+  case LibFunc_llrintl:
+  case LibFunc_llrint:
+    Changed|=setDoesNotThrow(F);
+    Changed|=setDoesNotAccessMemory(F);
+    Changed|=setWillReturn(F);
+    break;
   default:
     // FIXME: It'd be really nice to cover all the library functions we're
     // aware of here.
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 941e787f91eff..2e8ca90215455 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -3109,6 +3109,29 @@ Value *LibCallSimplifier::optimizeRemquo(CallInst *CI, IRBuilderBase &B) {
   return ConstantFP::get(CI->getType(), Rem);
 }
 
+
+Value *LibCallSimplifier::optimizellrint(CallInst *CI,IRBuilderBase &B){
+  const APFloat *X;
+  if(!match(CI->getOperand(0),m_APFloat(X))){
+    return nullptr;
+  }
+  Type *type=CI->getType();
+
+  unsigned width=type->getIntegerBitWidth();
+
+  APSInt Result(width,false);
+  bool Isexact;
+
+  APFloat::opStatus Status=X->convertToInteger(Result,APFloat::rmNearestTiesToEven,&Isexact);
+
+  if(Status==APFloat::opOK || Status==APFloat::opInexact){
+    return ConstantInt::get(type,Result);
+  }
+
+  return nullptr;
+
+}
+
 /// Constant folds fdim
 Value *LibCallSimplifier::optimizeFdim(CallInst *CI, IRBuilderBase &B) {
   // Cannot perform the fold unless the call has attribute memory(none)
@@ -4076,6 +4099,10 @@ Value *LibCallSimplifier::optimizeFloatingPointLibCall(CallInst *CI,
   case LibFunc_remquof:
   case LibFunc_remquol:
     return optimizeRemquo(CI, Builder);
+  case LibFunc_llrint:
+  case LibFunc_llrintf:   
+  case LibFunc_llrintl:
+    return optimizellrint(CI,Builder);
   case LibFunc_nan:
   case LibFunc_nanf:
   case LibFunc_nanl:
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index 9e56b01c6b315..3c85b8f64755d 100644
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -975,6 +975,16 @@ declare i32 @statvfs(ptr, ptr)
 ; CHECK-LINUX: declare noundef i32 @statvfs64(ptr noundef readonly captures(none), ptr noundef captures(none)) [[NOFREE_NOUNWIND]]
 declare i32 @statvfs64(ptr, ptr)
 
+; CHECK: declare noundef i64 @llrint(double) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare i64 @llrint(double)
+
+; CHECK: declare noundef i64 @llrintf(float) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare i64 @llrintf(float)
+
+; CHECK: declare noundef i64 @llrintl(x86_fp80) [[ERRNOMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
+declare i64 @llrintl(x86_fp80)
+
+
 ; CHECK: declare ptr @stpcpy(ptr noalias writeonly, ptr noalias readonly captures(none)) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare ptr @stpcpy(ptr, ptr)
 
diff --git a/llvm/test/Transforms/InstCombine/llrint_fold.ll b/llvm/test/Transforms/InstCombine/llrint_fold.ll
new file mode 100644
index 0000000000000..08cd4f66543a3
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/llrint_fold.ll
@@ -0,0 +1,87 @@
+; RUN: opt -S -passes=instcombine %s -o - | FileCheck %s
+
+
+declare i64 @llrint(double)
+
+; Positive number test
+; CHECK-LABEL: define i64 @test_llrint_pos()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 4
+define i64 @test_llrint_pos() {
+entry:
+  %val = call i64 @llrint(double 3.5)
+  ret i64 %val
+}
+
+; Negative number test
+; CHECK-LABEL: define i64 @test_llrint_neg()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 -2
+define i64 @test_llrint_neg() {
+entry:
+  %val = call i64 @llrint(double -2.5)
+  ret i64 %val
+}
+
+; Zero test
+; CHECK-LABEL: define i64 @test_llrint_zero()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 0
+define i64 @test_llrint_zero() {
+entry:
+  %val = call i64 @llrint(double 0.0)
+  ret i64 %val
+}
+
+; Large value test
+; CHECK-LABEL: define i64 @test_llrint_large()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 1000000
+define i64 @test_llrint_large() {
+entry:
+  %val = call i64 @llrint(double 1.0e6)
+  ret i64 %val
+}
+
+; Rounding test (check ties-to-even)
+; CHECK-LABEL: define i64 @test_llrint_round_even()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 2
+define i64 @test_llrint_round_even() {
+entry:
+  %val = call i64 @llrint(double 2.5)
+  ret i64 %val
+}
+
+; NaN test
+; CHECK-LABEL: define i64 @test_llrint_nan()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %val = call i64 @llrint(double 0x7FF8000000000000)
+; CHECK-NEXT:    ret i64 %val
+define i64 @test_llrint_nan() {
+entry:
+  %val = call i64 @llrint(double 0x7FF8000000000000) ; NaN
+  ret i64 %val
+}
+
+; +Inf test
+; CHECK-LABEL: define i64 @test_llrint_posinf()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %val = call i64 @llrint(double 0x7FF0000000000000)
+; CHECK-NEXT:    ret i64 %val
+define i64 @test_llrint_posinf() {
+entry:
+  %val = call i64 @llrint(double 0x7FF0000000000000) ; +Inf
+  ret i64 %val
+}
+
+; -Inf test
+; CHECK-LABEL: define i64 @test_llrint_neginf()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %val = call i64 @llrint(double 0xFFF0000000000000)
+; CHECK-NEXT:    ret i64 %val
+define i64 @test_llrint_neginf() {
+entry:
+  %val = call i64 @llrint(double 0xFFF0000000000000) ; -Inf
+  ret i64 %val
+}
diff --git a/llvm/test/Transforms/InstCombine/llrintf_fold.ll b/llvm/test/Transforms/InstCombine/llrintf_fold.ll
new file mode 100644
index 0000000000000..40cc265c1666c
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/llrintf_fold.ll
@@ -0,0 +1,33 @@
+; RUN: opt -S -passes=instcombine %s -o - | FileCheck %s
+
+declare i64 @llrintf(float)
+
+; Positive number test
+; CHECK-LABEL: define i64 @test_llrintf_pos()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 4
+define i64 @test_llrintf_pos() {
+entry:
+  %val = call i64 @llrintf(float 3.5)
+  ret i64 %val
+}
+
+; Negative number test
+; CHECK-LABEL: define i64 @test_llrintf_neg()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 -2
+define i64 @test_llrintf_neg() {
+entry:
+  %val = call i64 @llrintf(float -2.5)
+  ret i64 %val
+}
+
+; Zero test
+; CHECK-LABEL: define i64 @test_llrintf_zero()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 0
+define i64 @test_llrintf_zero() {
+entry:
+  %val = call i64 @llrintf(float 0.0)
+  ret i64 %val
+}
\ No newline at end of file
diff --git a/llvm/test/Transforms/InstCombine/llrintl_fp80.ll b/llvm/test/Transforms/InstCombine/llrintl_fp80.ll
new file mode 100644
index 0000000000000..a3e162ba5dac1
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/llrintl_fp80.ll
@@ -0,0 +1,65 @@
+; RUN: opt -S -passes=instcombine %s -o - | FileCheck %s
+declare i64 @llrintl(x86_fp80)
+
+; Positive number
+; CHECK-LABEL: define i64 @test_llrintl_pos()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 4
+define i64 @test_llrintl_pos() {
+entry:
+  %val = call i64 @llrintl(x86_fp80 0xK4000E000000000000000)
+  ret i64 %val
+}
+
+; Negative number
+; CHECK-LABEL: define i64 @test_llrintl_neg()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 -2
+define i64 @test_llrintl_neg() {
+entry:
+  %val = call i64 @llrintl(x86_fp80 0xKC000A000000000000000)
+  ret i64 %val
+}
+
+; Zero
+; CHECK-LABEL: define i64 @test_llrintl_zero()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    ret i64 0
+define i64 @test_llrintl_zero() {
+entry:
+  %val = call i64 @llrintl(x86_fp80 0xK00000000000000000000)
+  ret i64 %val
+}
+
+; NaN
+; CHECK-LABEL: define i64 @test_llrintl_nan()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %val = call i64 @llrintl(x86_fp80 0xK7FFF8000000000000000)
+; CHECK-NEXT:    ret i64 %val
+define i64 @test_llrintl_nan() {
+entry:
+  %val = call i64 @llrintl(x86_fp80 0xK7FFF8000000000000000)
+  ret i64 %val
+}
+
+; +Inf
+; CHECK-LABEL: define i64 @test_llrintl_posinf()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %val = call i64 @llrintl(x86_fp80 0xK7FFF0000000000000000)
+; CHECK-NEXT:    ret i64 %val
+define i64 @test_llrintl_posinf() {
+entry:
+  %val = call i64 @llrintl(x86_fp80 0xK7FFF0000000000000000)
+  ret i64 %val
+}
+
+; -Inf
+; CHECK-LABEL: define i64 @test_llrintl_neginf()
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %val = call i64 @llrintl(x86_fp80 0xKFFFF0000000000000000)
+; CHECK-NEXT:    ret i64 %val
+define i64 @test_llrintl_neginf() {
+entry:
+  %val = call i64 @llrintl(x86_fp80 0xKFFFF0000000000000000)
+  ret i64 %val
+}
diff --git a/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml b/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
index 2d23b15d74b17..4bc3adf7094a9 100644
--- 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: 274
 #
 # 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: 273
 #
 ## 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 523 symbols, 289 available
-# AVAIL-COUNT-289: {{^}} available
+# AVAIL: TLI knows 526 symbols, 292 available
+# AVAIL-COUNT-292: {{^}} available
 # AVAIL-NOT:       {{^}} available
 # UNAVAIL-COUNT-234: not available
 # UNAVAIL-NOT:       not available
@@ -842,6 +842,10 @@ DynamicSymbols:
     Type:            STT_FUNC
     Section:         .text
     Binding:         STB_GLOBAL
+  - Name:            llrint
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
   - Name:            remquof
     Type:            STT_FUNC
     Section:         .text
@@ -850,6 +854,18 @@ DynamicSymbols:
     Type:            STT_FUNC
     Section:         .text
     Binding:         STB_GLOBAL
+  - Name:            llrint
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            llrintf
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+  - Name:            llrintl
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL      
   - Name:            fdim
     Type:            STT_FUNC
     Section:         .text
diff --git a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
index 97722483aefe0..190467f5bed21 100644
--- a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
+++ b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
@@ -327,6 +327,9 @@ TEST_F(TargetLibraryInfoTest, ValidProto) {
       "declare double @remquo(double, double, ptr)\n"
       "declare float @remquof(float, float, ptr)\n"
       "declare x86_fp80 @remquol(x86_fp80, x86_fp80, ptr)\n"
+      "declare i64 @llrint(double)\n"
+      "declare i64 @llrintf(float)\n"
+      "declare i64 @llrintl(x86_fp80)\n"
       "declare double @fdim(double, double)\n"
       "declare float @fdimf(float, float)\n"
       "declare x86_fp80 @fdiml(x86_fp80, x86_fp80)\n"

nikic · 2025-08-21T19:29:32Z

Please rebase to resolve the merge conflict and format the code using git-clang-format.

llvm/include/llvm/Analysis/TargetLibraryInfo.def

nikic · 2025-08-21T19:30:23Z

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

+
+  return nullptr;
+
+}


As this is just constant folding, it should be in ConstantFolding.cpp.

since these are optimizing out the standard library calls i placed in simplifylibcalls.cpp

Still belongs in ConstantFolding

github-actions · 2025-08-21T21:37:58Z

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff HEAD~1 HEAD --extensions h,cpp -- llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h llvm/lib/Analysis/TargetLibraryInfo.cpp llvm/lib/Transforms/Utils/BuildLibCalls.cpp llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp llvm/unittests/Analysis/TargetLibraryInfoTest.cpp

View the diff from clang-format here.

diff --git a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
index 1c630783c..475e2f847 100644
--- a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
+++ b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
@@ -207,7 +207,7 @@ private:
   Value *optimizeLog(CallInst *CI, IRBuilderBase &B);
   Value *optimizeSqrt(CallInst *CI, IRBuilderBase &B);
   Value *optimizeFMod(CallInst *CI, IRBuilderBase &B);
-  Value *optimizellrint(CallInst *CI,IRBuilderBase &B);
+  Value *optimizellrint(CallInst *CI, IRBuilderBase &B);
   Value *mergeSqrtToExp(CallInst *CI, IRBuilderBase &B);
   Value *optimizeSinCosPi(CallInst *CI, bool IsSin, IRBuilderBase &B);
   Value *optimizeTrigInversionPairs(CallInst *CI, IRBuilderBase &B);
diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index 737d59081..c3faa4eae 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -1371,10 +1371,10 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
   case LibFunc_llrintf:
   case LibFunc_llrintl:
   case LibFunc_llrint:
-    Changed|=setDoesNotThrow(F);
-    Changed|=setDoesNotAccessMemory(F);
-    Changed|=setWillReturn(F);
-    break;  
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAccessMemory(F);
+    Changed |= setWillReturn(F);
+    break;
   case LibFunc_sincos:
   case LibFunc_sincosf:
   case LibFunc_sincosl:
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index f40a77145..59cd19c11 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -3111,26 +3111,26 @@ Value *LibCallSimplifier::optimizeRemquo(CallInst *CI, IRBuilderBase &B) {
   return ConstantFP::get(CI->getType(), Rem);
 }
 
-Value *LibCallSimplifier::optimizellrint(CallInst *CI,IRBuilderBase &B){
+Value *LibCallSimplifier::optimizellrint(CallInst *CI, IRBuilderBase &B) {
   const APFloat *X;
-  if(!match(CI->getOperand(0),m_APFloat(X))){
+  if (!match(CI->getOperand(0), m_APFloat(X))) {
     return nullptr;
   }
-  Type *type=CI->getType();
+  Type *type = CI->getType();
 
-  unsigned width=type->getIntegerBitWidth();
+  unsigned width = type->getIntegerBitWidth();
 
-  APSInt Result(width,false);
+  APSInt Result(width, false);
   bool Isexact;
 
-  APFloat::opStatus Status=X->convertToInteger(Result,APFloat::rmNearestTiesToEven,&Isexact);
+  APFloat::opStatus Status =
+      X->convertToInteger(Result, APFloat::rmNearestTiesToEven, &Isexact);
 
-  if(Status==APFloat::opOK || Status==APFloat::opInexact){
-    return ConstantInt::get(type,Result);
+  if (Status == APFloat::opOK || Status == APFloat::opInexact) {
+    return ConstantInt::get(type, Result);
   }
 
   return nullptr;
-
 }
 
 /// Constant folds fdim

pratheekhassan21 · 2025-08-22T05:01:03Z

@nikic i rebased and ran clang formatter on the code forgive my ignorance since this is my first contribution to llvm

arsenm

Why do you need to directly constant fold the libcalls? We have intrinsics for these, which we arguably should just always replace libcalls with

arsenm · 2025-08-22T15:09:15Z

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

+
+  return nullptr;
+
+}


Still belongs in ConstantFolding

nikic · 2025-08-22T16:41:59Z

Why do you need to directly constant fold the libcalls? We have intrinsics for these, which we arguably should just always replace libcalls with

This is a great question. I assumed this is because of the usual issue where the libcall may set errno and intrinsics don't. But these particular functions are specified to not set errno. (Edit: Well, at least that's what the man page says. It seems like the C standard does not specify this.)

The intrinsic is emitted if you use -fno-math-errno though. So I think these builtins may have just been misclassified in clang codegen and should be switched to emit the intrinsic unconditionally (not inside the GenerateIntrinsics conditional).

pratheekhassan21 · 2025-08-22T17:13:55Z

@arsenm do u suggest me to take back the pr and emit llrint intrinsics instead

pratheekhassan21 · 2025-08-24T21:06:18Z

@nikic i fixed the issues can u review it once

llvmbot added llvm:instcombine Covers the InstCombine, InstSimplify and AggressiveInstCombine passes llvm:analysis Includes value tracking, cost tables and constant folding llvm:transforms labels Aug 21, 2025

nikic changed the title ~~FIX:std::llrint,std::llrintf,std::llrintl compile time folding~~ [LLVM] Add constant folding for llrint, llrintf, llrintl Aug 21, 2025

nikic reviewed Aug 21, 2025

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pratheekhassan21 force-pushed the llrint-fix branch from 760e3cd to adbfbae Compare August 21, 2025 20:55

pratheekhassan21 force-pushed the llrint-fix branch from a0457cf to f4fd375 Compare August 22, 2025 04:56

dtcxzyw requested a review from arsenm August 22, 2025 14:52

arsenm reviewed Aug 22, 2025

View reviewed changes

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

return nullptr;

}

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Still belongs in ConstantFolding

arsenm added the floating-point Floating-point math label Aug 22, 2025

errors were fixed

98e7f6e

pratheekhassan21 force-pushed the llrint-fix branch from a1b14db to 98e7f6e Compare August 24, 2025 10:37

pratheekhassan21 added 2 commits August 24, 2025 16:08

Merge branch 'main' into llrint-fix

ebdd04f

Merge branch 'main' into llrint-fix

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