Fix implicit truncation of select non-bool vector conditions
#166279
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…non-bool condition tests
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@llvm/pr-subscribers-backend-x86 @llvm/pr-subscribers-hlsl Author: Kaitlin Peng (kmpeng) ChangesFixes #164018. The problem is that we're unable to do an implicit conversion sequence on a template deduced argument, so the current vector templates can't reconcile Full diff: https://github.com/llvm/llvm-project/pull/166279.diff 2 Files Affected:
diff --git a/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h b/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h
index a918af39e4074..3b4a94b97413a 100644
--- a/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h
+++ b/clang/lib/Headers/hlsl/hlsl_alias_intrinsics.h
@@ -2090,9 +2090,17 @@ T select(bool, T, T);
/// \param FalseVals The vector values are chosen from when conditions are
/// false.
-template <typename T, int Sz>
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+vector<T, 2> select(vector<bool, 2>, vector<T, 2>, vector<T, 2>);
+
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+vector<T, 3> select(vector<bool, 3>, vector<T, 3>, vector<T, 3>);
+
+template <typename T>
_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
-vector<T, Sz> select(vector<bool, Sz>, vector<T, Sz>, vector<T, Sz>);
+vector<T, 4> select(vector<bool, 4>, vector<T, 4>, vector<T, 4>);
/// \fn vector<T,Sz> select(vector<bool,Sz> Conds, T TrueVal,
/// vector<T,Sz> FalseVals)
@@ -2102,9 +2110,17 @@ vector<T, Sz> select(vector<bool, Sz>, vector<T, Sz>, vector<T, Sz>);
/// \param FalseVals The vector values are chosen from when conditions are
/// false.
-template <typename T, int Sz>
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+vector<T, 2> select(vector<bool, 2>, T, vector<T, 2>);
+
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+vector<T, 3> select(vector<bool, 3>, T, vector<T, 3>);
+
+template <typename T>
_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
-vector<T, Sz> select(vector<bool, Sz>, T, vector<T, Sz>);
+vector<T, 4> select(vector<bool, 4>, T, vector<T, 4>);
/// \fn vector<T,Sz> select(vector<bool,Sz> Conds, vector<T,Sz> TrueVals,
/// T FalseVal)
@@ -2113,9 +2129,17 @@ vector<T, Sz> select(vector<bool, Sz>, T, vector<T, Sz>);
/// \param TrueVals The vector values are chosen from when conditions are true.
/// \param FalseVal The scalar value to splat from when conditions are false.
-template <typename T, int Sz>
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+vector<T, 2> select(vector<bool, 2>, vector<T, 2>, T);
+
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+vector<T, 3> select(vector<bool, 3>, vector<T, 3>, T);
+
+template <typename T>
_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
-vector<T, Sz> select(vector<bool, Sz>, vector<T, Sz>, T);
+vector<T, 4> select(vector<bool, 4>, vector<T, 4>, T);
/// \fn vector<T,Sz> select(vector<bool,Sz> Conds, vector<T,Sz> TrueVals,
/// T FalseVal)
@@ -2124,10 +2148,20 @@ vector<T, Sz> select(vector<bool, Sz>, vector<T, Sz>, T);
/// \param TrueVal The scalar value to splat from when conditions are true.
/// \param FalseVal The scalar value to splat from when conditions are false.
-template <typename T, int Sz>
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+__detail::enable_if_t<__detail::is_arithmetic<T>::Value, vector<T, 2>> select(
+ vector<bool, 2>, T, T);
+
+template <typename T>
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
+__detail::enable_if_t<__detail::is_arithmetic<T>::Value, vector<T, 3>> select(
+ vector<bool, 3>, T, T);
+
+template <typename T>
_HLSL_BUILTIN_ALIAS(__builtin_hlsl_select)
-__detail::enable_if_t<__detail::is_arithmetic<T>::Value, vector<T, Sz>> select(
- vector<bool, Sz>, T, T);
+__detail::enable_if_t<__detail::is_arithmetic<T>::Value, vector<T, 4>> select(
+ vector<bool, 4>, T, T);
//===----------------------------------------------------------------------===//
// sin builtins
diff --git a/clang/test/CodeGenHLSL/builtins/select.hlsl b/clang/test/CodeGenHLSL/builtins/select.hlsl
index 7590b4a881259..e5169844cb3f2 100644
--- a/clang/test/CodeGenHLSL/builtins/select.hlsl
+++ b/clang/test/CodeGenHLSL/builtins/select.hlsl
@@ -20,16 +20,6 @@ struct S test_select_infer_struct(bool cond0, struct S tVal, struct S fVal) {
return select(cond0, tVal, fVal);
}
-// CHECK-LABEL: test_select_infer_array
-// CHECK: [[TRUE_VAL:%.*]] = load [3 x i32], ptr {{%.*}}, align 4
-// CHECK: [[FALSE_VAL:%.*]] = load [3 x i32], ptr {{%.*}}, align 4
-// CHECK: [[SELECT:%.*]] = select i1 {{%.*}}, [3 x i32] [[TRUE_VAL]], [3 x i32] [[FALSE_VAL]]
-// CHECK: store [3 x i32] [[SELECT]], ptr {{%.*}}, align 4
-// CHECK: ret void
-int test_select_infer_array(bool cond, int tVal[3], int fVal[3])[3] {
- return select(cond, tVal, fVal);
-}
-
// CHECK-LABEL: test_select_bool_vector
// CHECK: [[SELECT:%.*]] = select i1 {{%.*}}, <2 x i32> {{%.*}}, <2 x i32> {{%.*}}
// CHECK: ret <2 x i32> [[SELECT]]
@@ -38,24 +28,24 @@ int2 test_select_bool_vector(bool cond0, int2 tVal, int2 fVal) {
}
// CHECK-LABEL: test_select_vector_1
-// CHECK: [[SELECT:%.*]] = select <1 x i1> {{%.*}}, <1 x i32> {{%.*}}, <1 x i32> {{%.*}}
+// CHECK: [[SELECT:%.*]] = select i1 {{%.*}}, <1 x i32> {{%.*}}, <1 x i32> {{%.*}}
// CHECK: ret <1 x i32> [[SELECT]]
int1 test_select_vector_1(bool1 cond0, int1 tVals, int1 fVals) {
- return select<int,1>(cond0, tVals, fVals);
+ return select(cond0, tVals, fVals);
}
// CHECK-LABEL: test_select_vector_2
// CHECK: [[SELECT:%.*]] = select <2 x i1> {{%.*}}, <2 x i32> {{%.*}}, <2 x i32> {{%.*}}
// CHECK: ret <2 x i32> [[SELECT]]
int2 test_select_vector_2(bool2 cond0, int2 tVals, int2 fVals) {
- return select<int,2>(cond0, tVals, fVals);
+ return select(cond0, tVals, fVals);
}
// CHECK-LABEL: test_select_vector_3
// CHECK: [[SELECT:%.*]] = select <3 x i1> {{%.*}}, <3 x i32> {{%.*}}, <3 x i32> {{%.*}}
// CHECK: ret <3 x i32> [[SELECT]]
int3 test_select_vector_3(bool3 cond0, int3 tVals, int3 fVals) {
- return select<int,3>(cond0, tVals, fVals);
+ return select(cond0, tVals, fVals);
}
// CHECK-LABEL: test_select_vector_4
@@ -86,10 +76,54 @@ int4 test_select_vector_vector_scalar(bool4 cond0, int4 tVals, int fVal) {
// CHECK-LABEL: test_select_vector_scalar_scalar
// CHECK: [[SPLAT_SRC1:%.*]] = insertelement <4 x i32> poison, i32 {{%.*}}, i64 0
// CHECK: [[SPLAT1:%.*]] = shufflevector <4 x i32> [[SPLAT_SRC1]], <4 x i32> poison, <4 x i32> zeroinitializer
-// CHECK: [[SPLAT_SRC2:%.*]] = insertelement <4 x i32> poison, i32 %3, i64 0
+// CHECK: [[SPLAT_SRC2:%.*]] = insertelement <4 x i32> poison, i32 {{%.*}}, i64 0
// CHECK: [[SPLAT2:%.*]] = shufflevector <4 x i32> [[SPLAT_SRC2]], <4 x i32> poison, <4 x i32> zeroinitializer
// CHECK: [[SELECT:%.*]] = select <4 x i1> {{%.*}}, <4 x i32> [[SPLAT1]], <4 x i32> [[SPLAT2]]
// CHECK: ret <4 x i32> [[SELECT]]
int4 test_select_vector_scalar_scalar(bool4 cond0, int tVal, int fVal) {
return select(cond0, tVal, fVal);
}
+
+// CHECK-LABEL: test_select_nonbool_cond_vector_4
+// CHECK: [[TMP0:%.*]] = load <4 x i32>, ptr %cond0.addr, align 16
+// CHECK: [[TOBOOL:%.*]] = icmp ne <4 x i32> [[TMP0]], zeroinitializer
+// CHECK: [[SELECT:%.*]] = select <4 x i1> [[TOBOOL]], <4 x i1> {{%.*}}, <4 x i1> {{%.*}}
+// CHECK: ret <4 x i1> [[SELECT]]
+bool4 test_select_nonbool_cond_vector_4(int4 cond0, bool4 tVal, bool4 fVal) {
+ return select(cond0, tVal, fVal);
+}
+
+// CHECK-LABEL: test_select_nonbool_cond_vector_scalar_vector
+// CHECK: [[TMP0:%.*]] = load <3 x i32>, ptr %cond0.addr, align 16
+// CHECK: [[TOBOOL:%.*]] = icmp ne <3 x i32> [[TMP0]], zeroinitializer
+// CHECK: [[SPLAT_SRC1:%.*]] = insertelement <3 x i32> poison, i32 {{%.*}}, i64 0
+// CHECK: [[SPLAT1:%.*]] = shufflevector <3 x i32> [[SPLAT_SRC1]], <3 x i32> poison, <3 x i32> zeroinitializer
+// CHECK: [[SELECT:%.*]] = select <3 x i1> [[TOBOOL]], <3 x i32> [[SPLAT1]], <3 x i32> {{%.*}}
+// CHECK: ret <3 x i32> [[SELECT]]
+int3 test_select_nonbool_cond_vector_scalar_vector(int3 cond0, int tVal, int3 fVal) {
+ return select(cond0, tVal, fVal);
+}
+
+// CHECK-LABEL: test_select_nonbool_cond_vector_vector_scalar
+// CHECK: [[TMP0:%.*]] = load <2 x i32>, ptr %cond0.addr, align 8
+// CHECK: [[TOBOOL:%.*]] = icmp ne <2 x i32> [[TMP0]], zeroinitializer
+// CHECK: [[SPLAT_SRC1:%.*]] = insertelement <2 x i32> poison, i32 {{%.*}}, i64 0
+// CHECK: [[SPLAT1:%.*]] = shufflevector <2 x i32> [[SPLAT_SRC1]], <2 x i32> poison, <2 x i32> zeroinitializer
+// CHECK: [[SELECT:%.*]] = select <2 x i1> [[TOBOOL]], <2 x i32> {{%.*}}, <2 x i32> [[SPLAT1]]
+// CHECK: ret <2 x i32> [[SELECT]]
+int2 test_select_nonbool_cond_vector_vector_scalar(int2 cond0, int2 tVal, int fVal) {
+ return select(cond0, tVal, fVal);
+}
+
+// CHECK-LABEL: test_select_nonbool_cond_vector_scalar_scalar
+// CHECK: [[TMP0:%.*]] = load <4 x i32>, ptr %cond0.addr, align 16
+// CHECK: [[TOBOOL:%.*]] = icmp ne <4 x i32> [[TMP0]], zeroinitializer
+// CHECK: [[SPLAT_SRC1:%.*]] = insertelement <4 x i32> poison, i32 {{%.*}}, i64 0
+// CHECK: [[SPLAT1:%.*]] = shufflevector <4 x i32> [[SPLAT_SRC1]], <4 x i32> poison, <4 x i32> zeroinitializer
+// CHECK: [[SPLAT_SRC2:%.*]] = insertelement <4 x i32> poison, i32 {{%.*}}, i64 0
+// CHECK: [[SPLAT2:%.*]] = shufflevector <4 x i32> [[SPLAT_SRC2]], <4 x i32> poison, <4 x i32> zeroinitializer
+// CHECK: [[SELECT:%.*]] = select <4 x i1> [[TOBOOL]], <4 x i32> [[SPLAT1]], <4 x i32> [[SPLAT2]]
+// CHECK: ret <4 x i32> [[SELECT]]
+int4 test_select_nonbool_cond_vector_scalar_scalar(int4 cond0, int tVal, int fVal) {
+ return select(cond0, tVal, fVal);
+}
|
Icohedron
approved these changes
Nov 4, 2025
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Looks good to me. Should get a review from someone who knows more about long vectors though, and determine if/how we should come up with a general solution that would work with long vectors.
farzonl
approved these changes
Nov 4, 2025
Member
Not sure we have to worry about this yet. Much more than just select will need to be updated for long vectors. I think we can punt on that for now. |
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You don't need to change anything, but I was curious if HLSL_FIXED_VECTOR would help here? |
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If you mean just using |
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Fixes #164018.
The problem is that we're unable to do an implicit conversion sequence on a template deduced argument, so the current vector templates can't reconcile
vector<int, 4>withvector<bool, Sz>. This PR separates the vector templates into size-specific ones, getting rid of theSzdeduction and allowing for the implicit conversion to be done.