pengfei created this revision.
pengfei added reviewers: RKSimon, craig.topper, spatel.
pengfei requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
Intrinsics *reduce_add/mul_ps/pd have assumption that the elements in
the vector are reassociable. So we need to always assign the reassoc
flag when we call _mm_reduce_* intrinsics.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D96231
Files:
clang/lib/CodeGen/CGBuiltin.cpp
clang/lib/Headers/avx512fintrin.h
clang/test/CodeGen/X86/avx512-reduceIntrin.c
Index: clang/test/CodeGen/X86/avx512-reduceIntrin.c
===================================================================
--- clang/test/CodeGen/X86/avx512-reduceIntrin.c
+++ clang/test/CodeGen/X86/avx512-reduceIntrin.c
@@ -115,25 +115,25 @@
double test_mm512_reduce_add_pd(__m512d __W){
// CHECK-LABEL: @test_mm512_reduce_add_pd(
-// CHECK: call double @llvm.vector.reduce.fadd.v8f64(double 0.000000e+00, <8 x double> %{{.*}})
+// CHECK: call reassoc double @llvm.vector.reduce.fadd.v8f64(double 0.000000e+00, <8 x double> %{{.*}})
return _mm512_reduce_add_pd(__W);
}
double test_mm512_reduce_mul_pd(__m512d __W){
// CHECK-LABEL: @test_mm512_reduce_mul_pd(
-// CHECK: call double @llvm.vector.reduce.fmul.v8f64(double 1.000000e+00, <8 x double> %{{.*}})
+// CHECK: call reassoc double @llvm.vector.reduce.fmul.v8f64(double 1.000000e+00, <8 x double> %{{.*}})
return _mm512_reduce_mul_pd(__W);
}
float test_mm512_reduce_add_ps(__m512 __W){
// CHECK-LABEL: @test_mm512_reduce_add_ps(
-// CHECK: call float @llvm.vector.reduce.fadd.v16f32(float 0.000000e+00, <16 x float> %{{.*}})
+// CHECK: call reassoc float @llvm.vector.reduce.fadd.v16f32(float 0.000000e+00, <16 x float> %{{.*}})
return _mm512_reduce_add_ps(__W);
}
float test_mm512_reduce_mul_ps(__m512 __W){
// CHECK-LABEL: @test_mm512_reduce_mul_ps(
-// CHECK: call float @llvm.vector.reduce.fmul.v16f32(float 1.000000e+00, <16 x float> %{{.*}})
+// CHECK: call reassoc float @llvm.vector.reduce.fmul.v16f32(float 1.000000e+00, <16 x float> %{{.*}})
return _mm512_reduce_mul_ps(__W);
}
@@ -141,7 +141,7 @@
// CHECK-LABEL: @test_mm512_mask_reduce_add_pd(
// CHECK: bitcast i8 %{{.*}} to <8 x i1>
// CHECK: select <8 x i1> %{{.*}}, <8 x double> %{{.*}}, <8 x double> %{{.*}}
-// CHECK: call double @llvm.vector.reduce.fadd.v8f64(double 0.000000e+00, <8 x double> %{{.*}})
+// CHECK: call reassoc double @llvm.vector.reduce.fadd.v8f64(double 0.000000e+00, <8 x double> %{{.*}})
return _mm512_mask_reduce_add_pd(__M, __W);
}
@@ -149,7 +149,7 @@
// CHECK-LABEL: @test_mm512_mask_reduce_mul_pd(
// CHECK: bitcast i8 %{{.*}} to <8 x i1>
// CHECK: select <8 x i1> %{{.*}}, <8 x double> %{{.*}}, <8 x double> %{{.*}}
-// CHECK: call double @llvm.vector.reduce.fmul.v8f64(double 1.000000e+00, <8 x double> %{{.*}})
+// CHECK: call reassoc double @llvm.vector.reduce.fmul.v8f64(double 1.000000e+00, <8 x double> %{{.*}})
return _mm512_mask_reduce_mul_pd(__M, __W);
}
@@ -157,7 +157,7 @@
// CHECK-LABEL: @test_mm512_mask_reduce_add_ps(
// CHECK: bitcast i16 %{{.*}} to <16 x i1>
// CHECK: select <16 x i1> %{{.*}}, <16 x float> {{.*}}, <16 x float> {{.*}}
-// CHECK: call float @llvm.vector.reduce.fadd.v16f32(float 0.000000e+00, <16 x float> %{{.*}})
+// CHECK: call reassoc float @llvm.vector.reduce.fadd.v16f32(float 0.000000e+00, <16 x float> %{{.*}})
return _mm512_mask_reduce_add_ps(__M, __W);
}
@@ -165,6 +165,6 @@
// CHECK-LABEL: @test_mm512_mask_reduce_mul_ps(
// CHECK: bitcast i16 %{{.*}} to <16 x i1>
// CHECK: select <16 x i1> %{{.*}}, <16 x float> {{.*}}, <16 x float> %{{.*}}
-// CHECK: call float @llvm.vector.reduce.fmul.v16f32(float 1.000000e+00, <16 x float> %{{.*}})
+// CHECK: call reassoc float @llvm.vector.reduce.fmul.v16f32(float 1.000000e+00, <16 x float> %{{.*}})
return _mm512_mask_reduce_mul_ps(__M, __W);
}
Index: clang/lib/Headers/avx512fintrin.h
===================================================================
--- clang/lib/Headers/avx512fintrin.h
+++ clang/lib/Headers/avx512fintrin.h
@@ -9300,6 +9300,9 @@
* computations. In vector-reduction arithmetic, the evaluation off is
* independent of the order of the input elements of V.
+ * For floating points type, we always assume the elements are reassociable even
+ * if -fast-math is off.
+
* Used bisection method. At each step, we partition the vector with previous
* step in half, and the operation is performed on its two halves.
* This takes log2(n) steps where n is the number of elements in the vector.
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -13826,12 +13826,14 @@
case X86::BI__builtin_ia32_reduce_fadd_ps512: {
Function *F =
CGM.getIntrinsic(Intrinsic::vector_reduce_fadd, Ops[1]->getType());
+ Builder.getFastMathFlags().setAllowReassoc(true);
return Builder.CreateCall(F, {Ops[0], Ops[1]});
}
case X86::BI__builtin_ia32_reduce_fmul_pd512:
case X86::BI__builtin_ia32_reduce_fmul_ps512: {
Function *F =
CGM.getIntrinsic(Intrinsic::vector_reduce_fmul, Ops[1]->getType());
+ Builder.getFastMathFlags().setAllowReassoc(true);
return Builder.CreateCall(F, {Ops[0], Ops[1]});
}
case X86::BI__builtin_ia32_reduce_mul_d512:
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