Implement the `fmod` intrinsic #130320

kmpeng · 2025-03-07T18:31:07Z

Replaced the current fmod definition with a templatized version, implemented fmod algorithm for DirectX targets that matches the DXC implementation, added corresponding tests in clang/test/CodeGenHLSL/builtins/fmod.hlsl and clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl.

Closes #99118.

github-actions · 2025-03-07T18:31:26Z

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llvmbot · 2025-03-07T18:32:00Z

@llvm/pr-subscribers-clang
@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-hlsl

Author: Kaitlin Peng (kmpeng)

Changes

Replaced the current fmod definition with a templatized version, implemented fmod algorithm for DirectX targets that matches the DXC implementation, added corresponding tests in clang/test/CodeGenHLSL/builtins/fmod.hlsl and clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl.

Full diff: https://github.com/llvm/llvm-project/pull/130320.diff

5 Files Affected:

(modified) clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h (-34)
(modified) clang/lib/Headers/hlsl/hlsl_detail.h (+25)
(modified) clang/lib/Headers/hlsl/hlsl_intrinsics.h (+32)
(modified) clang/test/CodeGenHLSL/builtins/fmod.hlsl (+111-23)
(added) clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl (+33)

diff --git a/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h b/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h
index 7573f6e024167..cd59fef82d9f9 100644
--- a/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h
+++ b/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h
@@ -1237,40 +1237,6 @@ float3 floor(float3);
 _HLSL_BUILTIN_ALIAS(__builtin_elementwise_floor)
 float4 floor(float4);
 
-//===----------------------------------------------------------------------===//
-// fmod builtins
-//===----------------------------------------------------------------------===//
-
-/// \fn T fmod(T x, T y)
-/// \brief Returns the linear interpolation of x to y.
-/// \param x [in] The dividend.
-/// \param y [in] The divisor.
-///
-/// Return the floating-point remainder of the x parameter divided by the y
-/// parameter.
-
-_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-half fmod(half, half);
-_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-half2 fmod(half2, half2);
-_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-half3 fmod(half3, half3);
-_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-half4 fmod(half4, half4);
-
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-float fmod(float, float);
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-float2 fmod(float2, float2);
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-float3 fmod(float3, float3);
-_HLSL_BUILTIN_ALIAS(__builtin_elementwise_fmod)
-float4 fmod(float4, float4);
-
 //===----------------------------------------------------------------------===//
 // frac builtins
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Headers/hlsl/hlsl_detail.h b/clang/lib/Headers/hlsl/hlsl_detail.h
index 39254a3cc3a0a..470cc4db24cd2 100644
--- a/clang/lib/Headers/hlsl/hlsl_detail.h
+++ b/clang/lib/Headers/hlsl/hlsl_detail.h
@@ -97,6 +97,31 @@ constexpr vector<T, L> reflect_vec_impl(vector<T, L> I, vector<T, L> N) {
 #endif
 }
 
+template <typename T>
+constexpr enable_if_t<is_same<float, T>::value || is_same<half, T>::value, T>
+fmod_impl(T X, T Y) {
+#if !defined(__DIRECTX__)
+  return __builtin_elementwise_fmod(X, Y);
+#else 
+  T div = X / Y;
+  bool ge = div >= -div;
+  T frc = frac(abs(div));
+  return select<T>(ge, frc, -frc) * Y;
+#endif
+}
+
+template <typename T, int N>
+constexpr vector<T, N> fmod_vec_impl(vector<T, N> X, vector<T, N> Y) {
+#if !defined(__DIRECTX__)
+  return __builtin_elementwise_fmod(X, Y);
+#else 
+  vector<T, N> div = X / Y;
+  vector<bool, N> ge = div >= -div;
+  vector<T, N> frc = frac(abs(div)); 
+  return select<T>(ge, frc, -frc) * Y;
+#endif
+}
+
 } // namespace __detail
 } // namespace hlsl
 #endif //_HLSL_HLSL_DETAILS_H_
diff --git a/clang/lib/Headers/hlsl/hlsl_intrinsics.h b/clang/lib/Headers/hlsl/hlsl_intrinsics.h
index fe9441080433d..3393c955e9a4b 100644
--- a/clang/lib/Headers/hlsl/hlsl_intrinsics.h
+++ b/clang/lib/Headers/hlsl/hlsl_intrinsics.h
@@ -109,6 +109,38 @@ const inline float distance(vector<float, N> X, vector<float, N> Y) {
   return __detail::distance_vec_impl(X, Y);
 }
 
+//===----------------------------------------------------------------------===//
+// fmod builtins
+//===----------------------------------------------------------------------===//
+
+/// \fn T fmod(T x, T y)
+/// \brief Returns the linear interpolation of x to y.
+/// \param x [in] The dividend.
+/// \param y [in] The divisor.
+///
+/// Return the floating-point remainder of the x parameter divided by the y
+/// parameter.
+
+_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
+const inline half fmod(half X, half Y) {
+  return __detail::fmod_impl(X, Y);
+}
+
+const inline float fmod(float X, float Y) {
+  return __detail::fmod_impl(X, Y);
+}
+
+template <int N>
+_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
+const inline vector<half, N> fmod(vector<half, N> X, vector<half, N> Y) {
+  return __detail::fmod_vec_impl(X, Y);
+}
+
+template <int N>
+const inline vector<float, N> fmod(vector<float, N> X, vector<float, N> Y) {
+  return __detail::fmod_vec_impl(X, Y);
+}
+
 //===----------------------------------------------------------------------===//
 // length builtins
 //===----------------------------------------------------------------------===//
diff --git a/clang/test/CodeGenHLSL/builtins/fmod.hlsl b/clang/test/CodeGenHLSL/builtins/fmod.hlsl
index b62967114d456..359463b914c98 100644
--- a/clang/test/CodeGenHLSL/builtins/fmod.hlsl
+++ b/clang/test/CodeGenHLSL/builtins/fmod.hlsl
@@ -4,16 +4,16 @@
 //
 // RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \
 // RUN:   dxil-pc-shadermodel6.3-library %s -fnative-half-type \
-// RUN:   -emit-llvm -disable-llvm-passes -o - | FileCheck %s \
-// RUN:   -DFNATTRS="noundef nofpclass(nan inf)" -DTYPE=half
+// RUN:   -emit-llvm -o - | FileCheck %s -DFNATTRS="noundef nofpclass(nan inf)" \
+// RUN:   -DTYPE=half --check-prefixes=DXCHECK,DXNATIVE_HALF
 
 //
 // ---------- No Native Half support test -----------
 //
 // RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \
-// RUN:   dxil-pc-shadermodel6.3-library %s -emit-llvm -disable-llvm-passes \
-// RUN:   -o - | FileCheck %s \
-// RUN:   -DFNATTRS="noundef nofpclass(nan inf)" -DTYPE=float
+// RUN:   dxil-pc-shadermodel6.3-library %s -emit-llvm \
+// RUN:   -o - | FileCheck %s -DFNATTRS="noundef nofpclass(nan inf)" \
+// RUN:   -DTYPE=float --check-prefixes=DXCHECK,DXNO_HALF
 
 
 // Spirv target:
@@ -22,56 +22,144 @@
 //
 // RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \
 // RUN:   spirv-unknown-vulkan-compute %s -fnative-half-type \
-// RUN:   -emit-llvm -disable-llvm-passes -o - | FileCheck %s \
+// RUN:   -emit-llvm -o - | FileCheck %s \
 // RUN:   -DFNATTRS="spir_func noundef nofpclass(nan inf)" -DTYPE=half
 
 //
 // ---------- No Native Half support test -----------
 //
 // RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \
-// RUN:   spirv-unknown-vulkan-compute %s -emit-llvm -disable-llvm-passes \
+// RUN:   spirv-unknown-vulkan-compute %s -emit-llvm \
 // RUN:   -o - | FileCheck %s \
 // RUN:   -DFNATTRS="spir_func noundef nofpclass(nan inf)" -DTYPE=float
 
 
 
+// DXCHECK: define [[FNATTRS]] [[TYPE]] @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn [[TYPE]]
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn [[TYPE]]
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge [[TYPE]]
+// DXNATIVE_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn [[TYPE]] @llvm.fabs.f16([[TYPE]]
+// DXNO_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn [[TYPE]] @llvm.fabs.f32([[TYPE]]
+// DXNATIVE_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn [[TYPE]] @llvm.dx.frac.f16([[TYPE]]
+// DXNO_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn [[TYPE]] @llvm.dx.frac.f32([[TYPE]]
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn [[TYPE]]
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn i1
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn [[TYPE]]
+// DXCHECK: ret [[TYPE]] %mul.i
 // CHECK: define [[FNATTRS]] [[TYPE]] @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn [[TYPE]]
-// CHECK: ret [[TYPE]] %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn [[TYPE]]
+// CHECK: ret [[TYPE]] %fmod.i
 half test_fmod_half(half p0, half p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] <2 x [[TYPE]]> @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]>
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]>
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge <2 x [[TYPE]]>
+// DXNATIVE_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]> @llvm.fabs.v2f16(<2 x [[TYPE]]>
+// DXNO_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]> @llvm.fabs.v2f32(<2 x [[TYPE]]>
+// DXNATIVE_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]> @llvm.dx.frac.v2f16(<2 x [[TYPE]]>
+// DXNO_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]> @llvm.dx.frac.v2f32(<2 x [[TYPE]]>
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]>
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn <2 x i1>
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]>
+// DXCHECK: ret <2 x [[TYPE]]> %mul.i
 // CHECK: define [[FNATTRS]] <2 x [[TYPE]]> @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]>
-// CHECK: ret <2 x [[TYPE]]> %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn <2 x [[TYPE]]>
+// CHECK: ret <2 x [[TYPE]]> %fmod.i
 half2 test_fmod_half2(half2 p0, half2 p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] <3 x [[TYPE]]> @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]>
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]>
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge <3 x [[TYPE]]>
+// DXNATIVE_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]> @llvm.fabs.v3f16(<3 x [[TYPE]]>
+// DXNO_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]> @llvm.fabs.v3f32(<3 x [[TYPE]]>
+// DXNATIVE_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]> @llvm.dx.frac.v3f16(<3 x [[TYPE]]>
+// DXNO_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]> @llvm.dx.frac.v3f32(<3 x [[TYPE]]>
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]>
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn <3 x i1>
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]>
+// DXCHECK: ret <3 x [[TYPE]]> %mul.i
 // CHECK: define [[FNATTRS]] <3 x [[TYPE]]> @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]>
-// CHECK: ret <3 x [[TYPE]]> %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn <3 x [[TYPE]]>
+// CHECK: ret <3 x [[TYPE]]> %fmod.i
 half3 test_fmod_half3(half3 p0, half3 p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] <4 x [[TYPE]]> @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]>
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]>
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge <4 x [[TYPE]]>
+// DXNATIVE_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]> @llvm.fabs.v4f16(<4 x [[TYPE]]>
+// DXNO_HALF: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]> @llvm.fabs.v4f32(<4 x [[TYPE]]>
+// DXNATIVE_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]> @llvm.dx.frac.v4f16(<4 x [[TYPE]]>
+// DXNO_HALF: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]> @llvm.dx.frac.v4f32(<4 x [[TYPE]]>
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]>
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn <4 x i1>
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]>
+// DXCHECK: ret <4 x [[TYPE]]> %mul.i
 // CHECK: define [[FNATTRS]] <4 x [[TYPE]]> @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]>
-// CHECK: ret <4 x [[TYPE]]> %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn <4 x [[TYPE]]>
+// CHECK: ret <4 x [[TYPE]]> %fmod.i
 half4 test_fmod_half4(half4 p0, half4 p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] float @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn float
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn float
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge float
+// DXCHECK: %elt.abs.i = call reassoc nnan ninf nsz arcp afn float @llvm.fabs.f32(float
+// DXCHECK: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn float @llvm.dx.frac.f32(float
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn float
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn i1 
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn float 
+// DXCHECK: ret float %mul.i
 // CHECK: define [[FNATTRS]] float @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn float
-// CHECK: ret float %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn float
+// CHECK: ret float %fmod.i
 float test_fmod_float(float p0, float p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] <2 x float> @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn <2 x float>
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn <2 x float>
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge <2 x float>
+// DXCHECK: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <2 x float> @llvm.fabs.v2f32(<2 x float>
+// DXCHECK: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <2 x float> @llvm.dx.frac.v2f32(<2 x float>
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn <2 x float>
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn <2 x i1>
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn <2 x float>
+// DXCHECK: ret <2 x float> %mul.i
 // CHECK: define [[FNATTRS]] <2 x float> @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn <2 x float>
-// CHECK: ret <2 x float> %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn <2 x float>
+// CHECK: ret <2 x float> %fmod.i
 float2 test_fmod_float2(float2 p0, float2 p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] <3 x float> @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn <3 x float>
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn <3 x float>
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge <3 x float>
+// DXCHECK: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <3 x float> @llvm.fabs.v3f32(<3 x float>
+// DXCHECK: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <3 x float> @llvm.dx.frac.v3f32(<3 x float>
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn <3 x float>
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn <3 x i1>
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn <3 x float>
+// DXCHECK: ret <3 x float> %mul.i
 // CHECK: define [[FNATTRS]] <3 x float> @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn <3 x float>
-// CHECK: ret <3 x float> %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn <3 x float>
+// CHECK: ret <3 x float> %fmod.i
 float3 test_fmod_float3(float3 p0, float3 p1) { return fmod(p0, p1); }
 
+// DXCHECK: define [[FNATTRS]] <4 x float> @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn <4 x float>
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn <4 x float>
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge <4 x float>
+// DXCHECK: %elt.abs.i = call reassoc nnan ninf nsz arcp afn <4 x float> @llvm.fabs.v4f32(<4 x float>
+// DXCHECK: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn <4 x float> @llvm.dx.frac.v4f32(<4 x float>
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn <4 x float>
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn <4 x i1>
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn <4 x float>
+// DXCHECK: ret <4 x float> %mul.i
 // CHECK: define [[FNATTRS]] <4 x float> @
-// CHECK: %fmod = frem reassoc nnan ninf nsz arcp afn <4 x float>
-// CHECK: ret <4 x float> %fmod
+// CHECK: %fmod.i = frem reassoc nnan ninf nsz arcp afn <4 x float>
+// CHECK: ret <4 x float> %fmod.i
 float4 test_fmod_float4(float4 p0, float4 p1) { return fmod(p0, p1); }
 
diff --git a/clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl b/clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl
new file mode 100644
index 0000000000000..86f5a6f7bea9c
--- /dev/null
+++ b/clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl
@@ -0,0 +1,33 @@
+// RUN: %clang_cc1 -finclude-default-header -x hlsl -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm-only -disable-llvm-passes -verify
+
+float test_no_second_arg(float2 p0) {
+  return fmod(p0);
+  // expected-error@-1 {{no matching function for call to 'fmod'}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires 2 arguments, but 1 was provided}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires 2 arguments, but 1 was provided}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires 2 arguments, but 1 was provided}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires 2 arguments, but 1 was provided}}
+}
+
+float test_too_many_arg(float2 p0) {
+  return fmod(p0, p0, p0);
+  // expected-error@-1 {{no matching function for call to 'fmod'}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires 2 arguments, but 3 were provided}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires 2 arguments, but 3 were provided}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires 2 arguments, but 3 were provided}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires 2 arguments, but 3 were provided}}
+}
+
+float test_double_inputs(double p0, double p1) {
+  return fmod(p0, p1);
+  // expected-error@-1  {{call to 'fmod' is ambiguous}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function}}
+}
+
+float test_int_inputs(int p0, int p1) {
+  return fmod(p0, p1);
+  // expected-error@-1  {{call to 'fmod' is ambiguous}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function}}
+  // expected-note@hlsl/hlsl_intrinsics.h:* {{candidate function}}
+}

Icohedron

For the most part, this PR looks good! Just needs some changes to the codegen test to make it more clear that the implementation is correctly being tested.

clang/test/CodeGenHLSL/builtins/fmod.hlsl

github-actions · 2025-03-07T21:17:11Z

✅ With the latest revision this PR passed the C/C++ code formatter.

clang/test/CodeGenHLSL/builtins/fmod.hlsl

clang/lib/Headers/hlsl/hlsl_detail.h

clang/test/CodeGenHLSL/builtins/fmod.hlsl

farzonl · 2025-03-12T03:53:46Z

@kmpeng could you rebase and squash these commits. If I try and squash merge its going to set your personal email as the author because your first commit was using your personal: https://github.com/llvm/llvm-project/commit/ef16da4479d9d2034f3b6072410b488d7568ce88.patch

but looks like you switch to your work email later: https://github.com/llvm/llvm-project/commit/bd1a02b0e7bacf1ecbc54de8356aef0a5df8bd5d.patch

The only way I know how to fix this is if the first commit was using your work email hence my ask to rebase and squash to one commit.

…w fmod-directx.hlsl test file, removed directx tests from fmod.hlsl

…irv tests

… fmod-directx.hlsl tests

…sl tests, formatted files with clang-format

…l.h changes to hlsl_intrinsic_helpers.h

github-actions · 2025-03-12T17:21:28Z

@kmpeng Congratulations on having your first Pull Request (PR) merged into the LLVM Project!

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Replaced the current `fmod` definition with a templatized version, implemented `fmod` algorithm for DirectX targets that matches the DXC implementation, added corresponding tests in `clang/test/CodeGenHLSL/builtins/fmod.hlsl` and `clang/test/SemaHLSL/BuiltIns/fmod-errors.hlsl`. Closes llvm#99118.

llvmbot added clang Clang issues not falling into any other category backend:X86 clang:headers Headers provided by Clang, e.g. for intrinsics HLSL HLSL Language Support labels Mar 7, 2025

Icohedron requested changes Mar 7, 2025

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kmpeng force-pushed the users/kmpeng/fmod_intrinsic branch from f39f647 to f190de5 Compare March 10, 2025 20:31

farzonl approved these changes Mar 10, 2025

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kmpeng force-pushed the users/kmpeng/fmod_intrinsic branch 2 times, most recently from fd36c1f to 214cb4a Compare March 10, 2025 21:27

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farzonl requested a review from Icohedron March 12, 2025 00:39

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kmpeng force-pushed the users/kmpeng/fmod_intrinsic branch from bd1a02b to 4b62159 Compare March 12, 2025 16:38

kmpeng added 7 commits March 12, 2025 09:53

start implementation

73ec3fa

finished implementation, working on fmod.hlsl tests

f7cee38

tweaked implementation to exclude vec1 & restrict to vec4, created ne…

67cdd8c

…w fmod-directx.hlsl test file, removed directx tests from fmod.hlsl

fixed hlsl_intrinsics header return types, disabled llvm passes in sp…

c1b03d7

…irv tests

Modified implementation after reorganization of instrinsics, finished…

8b1b2a4

… fmod-directx.hlsl tests

Added fmod Sema error checks

5a131ae

Merge fmod-directx.hlsl tests back into fmod.hlsl

1d71437

kmpeng added 4 commits March 12, 2025 09:53

Added SPVCHECK prefix & changed function definition checks in fmod.hl…

fc0d9f0

…sl tests, formatted files with clang-format

Modify fmod.hlsl tests to include operands of each instruction

567d8bb

updated fmod.hlsl test cases following feedback, move fmod hlsl_detai…

f31cae5

…l.h changes to hlsl_intrinsic_helpers.h

wild card out ambiguous registers, simplify fmod algorithm

8aeb5bd

kmpeng force-pushed the users/kmpeng/fmod_intrinsic branch from 4b62159 to 8aeb5bd Compare March 12, 2025 16:56

farzonl merged commit 184f944 into llvm:main Mar 12, 2025
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kmpeng mentioned this pull request Mar 31, 2025

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Implement the `fmod` intrinsic #130320

Implement the `fmod` intrinsic #130320

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Implement the fmod intrinsic #130320

Implement the fmod intrinsic #130320

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Implement the `fmod` intrinsic #130320

Implement the `fmod` intrinsic #130320

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