[clang] 15edd7a - [FPEnv] PowerPC-specific builtin constrained FP enablement

Kevin P. Neal via cfe-commits cfe-commits at lists.llvm.org
Thu Jun 25 08:48:03 PDT 2020


Author: Andrew Wock
Date: 2020-06-25T11:42:58-04:00
New Revision: 15edd7aaa7142e5db2a6cf9b81e4514967431824

URL: https://github.com/llvm/llvm-project/commit/15edd7aaa7142e5db2a6cf9b81e4514967431824
DIFF: https://github.com/llvm/llvm-project/commit/15edd7aaa7142e5db2a6cf9b81e4514967431824.diff

LOG: [FPEnv] PowerPC-specific builtin constrained FP enablement

This change enables PowerPC compiler builtins to generate constrained
floating point operations when clang is indicated to do so.

A couple of possibly unexpected backend divergences between constrained
floating point and regular behavior are highlighted under the test tag
FIXME-CHECK. This may be something for those on the PPC backend to look
at.

Patch by: Drew Wock <drew.wock at sas.com>

Differential Revision: https://reviews.llvm.org/D82020

Added: 
    clang/test/CodeGen/builtins-ppc-fpconstrained.c

Modified: 
    clang/lib/CodeGen/CGBuiltin.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 89ab1a3c2cb0..c43877e117eb 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -14235,9 +14235,14 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
   case PPC::BI__builtin_vsx_xvsqrtdp: {
     llvm::Type *ResultType = ConvertType(E->getType());
     Value *X = EmitScalarExpr(E->getArg(0));
-    ID = Intrinsic::sqrt;
-    llvm::Function *F = CGM.getIntrinsic(ID, ResultType);
-    return Builder.CreateCall(F, X);
+    if (Builder.getIsFPConstrained()) {
+      llvm::Function *F = CGM.getIntrinsic(
+          Intrinsic::experimental_constrained_sqrt, ResultType);
+      return Builder.CreateConstrainedFPCall(F, X);
+    } else {
+      llvm::Function *F = CGM.getIntrinsic(Intrinsic::sqrt, ResultType);
+      return Builder.CreateCall(F, X);
+    }
   }
   // Count leading zeros
   case PPC::BI__builtin_altivec_vclzb:
@@ -14294,21 +14299,32 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
     Value *X = EmitScalarExpr(E->getArg(0));
     if (BuiltinID == PPC::BI__builtin_vsx_xvrdpim ||
         BuiltinID == PPC::BI__builtin_vsx_xvrspim)
-      ID = Intrinsic::floor;
+      ID = Builder.getIsFPConstrained()
+               ? Intrinsic::experimental_constrained_floor
+               : Intrinsic::floor;
     else if (BuiltinID == PPC::BI__builtin_vsx_xvrdpi ||
              BuiltinID == PPC::BI__builtin_vsx_xvrspi)
-      ID = Intrinsic::round;
+      ID = Builder.getIsFPConstrained()
+               ? Intrinsic::experimental_constrained_round
+               : Intrinsic::round;
     else if (BuiltinID == PPC::BI__builtin_vsx_xvrdpic ||
              BuiltinID == PPC::BI__builtin_vsx_xvrspic)
-      ID = Intrinsic::nearbyint;
+      ID = Builder.getIsFPConstrained()
+               ? Intrinsic::experimental_constrained_nearbyint
+               : Intrinsic::nearbyint;
     else if (BuiltinID == PPC::BI__builtin_vsx_xvrdpip ||
              BuiltinID == PPC::BI__builtin_vsx_xvrspip)
-      ID = Intrinsic::ceil;
+      ID = Builder.getIsFPConstrained()
+               ? Intrinsic::experimental_constrained_ceil
+               : Intrinsic::ceil;
     else if (BuiltinID == PPC::BI__builtin_vsx_xvrdpiz ||
              BuiltinID == PPC::BI__builtin_vsx_xvrspiz)
-      ID = Intrinsic::trunc;
+      ID = Builder.getIsFPConstrained()
+               ? Intrinsic::experimental_constrained_trunc
+               : Intrinsic::trunc;
     llvm::Function *F = CGM.getIntrinsic(ID, ResultType);
-    return Builder.CreateCall(F, X);
+    return Builder.getIsFPConstrained() ? Builder.CreateConstrainedFPCall(F, X)
+                                        : Builder.CreateCall(F, X);
   }
 
   // Absolute value
@@ -14333,21 +14349,43 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
     Value *X = EmitScalarExpr(E->getArg(0));
     Value *Y = EmitScalarExpr(E->getArg(1));
     Value *Z = EmitScalarExpr(E->getArg(2));
-    llvm::Function *F = CGM.getIntrinsic(Intrinsic::fma, ResultType);
+    llvm::Function *F;
+    if (Builder.getIsFPConstrained())
+      F = CGM.getIntrinsic(Intrinsic::experimental_constrained_fma, ResultType);
+    else
+      F = CGM.getIntrinsic(Intrinsic::fma, ResultType);
     switch (BuiltinID) {
       case PPC::BI__builtin_vsx_xvmaddadp:
       case PPC::BI__builtin_vsx_xvmaddasp:
-        return Builder.CreateCall(F, {X, Y, Z});
+        if (Builder.getIsFPConstrained())
+          return Builder.CreateConstrainedFPCall(F, {X, Y, Z});
+        else
+          return Builder.CreateCall(F, {X, Y, Z});
       case PPC::BI__builtin_vsx_xvnmaddadp:
       case PPC::BI__builtin_vsx_xvnmaddasp:
-        return Builder.CreateFNeg(Builder.CreateCall(F, {X, Y, Z}), "neg");
+        if (Builder.getIsFPConstrained())
+          return Builder.CreateFNeg(
+              Builder.CreateConstrainedFPCall(F, {X, Y, Z}), "neg");
+        else
+          return Builder.CreateFNeg(Builder.CreateCall(F, {X, Y, Z}), "neg");
       case PPC::BI__builtin_vsx_xvmsubadp:
       case PPC::BI__builtin_vsx_xvmsubasp:
-        return Builder.CreateCall(F, {X, Y, Builder.CreateFNeg(Z, "neg")});
+        if (Builder.getIsFPConstrained())
+          return Builder.CreateConstrainedFPCall(
+              F, {X, Y, Builder.CreateFNeg(Z, "neg")});
+        else
+          return Builder.CreateCall(F, {X, Y, Builder.CreateFNeg(Z, "neg")});
       case PPC::BI__builtin_vsx_xvnmsubadp:
       case PPC::BI__builtin_vsx_xvnmsubasp:
-        return Builder.CreateFNeg(
-            Builder.CreateCall(F, {X, Y, Builder.CreateFNeg(Z, "neg")}), "neg");
+        if (Builder.getIsFPConstrained())
+          return Builder.CreateFNeg(
+              Builder.CreateConstrainedFPCall(
+                  F, {X, Y, Builder.CreateFNeg(Z, "neg")}),
+              "neg");
+        else
+          return Builder.CreateFNeg(
+              Builder.CreateCall(F, {X, Y, Builder.CreateFNeg(Z, "neg")}),
+              "neg");
     }
     llvm_unreachable("Unknown FMA operation");
     return nullptr; // Suppress no-return warning

diff  --git a/clang/test/CodeGen/builtins-ppc-fpconstrained.c b/clang/test/CodeGen/builtins-ppc-fpconstrained.c
new file mode 100644
index 000000000000..38cdfb6aab38
--- /dev/null
+++ b/clang/test/CodeGen/builtins-ppc-fpconstrained.c
@@ -0,0 +1,159 @@
+// REQUIRES: powerpc-registered-target
+// RUN: %clang_cc1 -triple powerpc64le-gnu-linux -target-feature +vsx \
+// RUN: -emit-llvm %s -o - | FileCheck --check-prefix=CHECK-UNCONSTRAINED %s
+// RUN: %clang_cc1 -triple powerpc64le-gnu-linux -target-feature +vsx \
+// RUN:  -ffp-exception-behavior=strict -emit-llvm %s -o - | FileCheck \
+// RUN: --check-prefix=CHECK-CONSTRAINED -vv %s
+// RUN: %clang_cc1 -triple powerpc64le-gnu-linux -target-feature +vsx \
+// RUN: -fallow-half-arguments-and-returns -S -o - %s | \
+// RUN: FileCheck --check-prefix=CHECK-ASM --check-prefix=NOT-FIXME-CHECK  %s
+// RUN: %clang_cc1 -triple powerpc64le-gnu-linux -target-feature +vsx \
+// RUN: -fallow-half-arguments-and-returns -S -ffp-exception-behavior=strict \
+// RUN: -o - %s | FileCheck --check-prefix=CHECK-ASM \
+// RUN: --check-prefix=FIXME-CHECK  %s
+
+typedef __attribute__((vector_size(4 * sizeof(float)))) float vec_float;
+typedef __attribute__((vector_size(2 * sizeof(double)))) double vec_double;
+
+volatile vec_double vd;
+volatile vec_float vf;
+
+void test_float(void) {
+  vf = __builtin_vsx_xvsqrtsp(vf);
+  // CHECK-LABEL: try-xvsqrtsp
+  // CHECK-UNCONSTRAINED: @llvm.sqrt.v4f32(<4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.sqrt.v4f32(<4 x float> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvsqrtsp
+
+  vd = __builtin_vsx_xvsqrtdp(vd);
+  // CHECK-LABEL: try-xvsqrtdp
+  // CHECK-UNCONSTRAINED: @llvm.sqrt.v2f64(<2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.sqrt.v2f64(<2 x double> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvsqrtdp
+
+  vf = __builtin_vsx_xvrspim(vf);
+  // CHECK-LABEL: try-xvrspim
+  // CHECK-UNCONSTRAINED: @llvm.floor.v4f32(<4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.floor.v4f32(<4 x float> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrspim
+
+  vd = __builtin_vsx_xvrdpim(vd);
+  // CHECK-LABEL: try-xvrdpim
+  // CHECK-UNCONSTRAINED: @llvm.floor.v2f64(<2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.floor.v2f64(<2 x double> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrdpim
+
+  vf = __builtin_vsx_xvrspi(vf);
+  // CHECK-LABEL: try-xvrspi
+  // CHECK-UNCONSTRAINED: @llvm.round.v4f32(<4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.round.v4f32(<4 x float> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrspi
+
+  vd = __builtin_vsx_xvrdpi(vd);
+  // CHECK-LABEL: try-xvrdpi
+  // CHECK-UNCONSTRAINED: @llvm.round.v2f64(<2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.round.v2f64(<2 x double> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrdpi
+
+  vf = __builtin_vsx_xvrspic(vf);
+  // CHECK-LABEL: try-xvrspic
+  // CHECK-UNCONSTRAINED: @llvm.nearbyint.v4f32(<4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.nearbyint.v4f32(<4 x float> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrspic
+
+  vd = __builtin_vsx_xvrdpic(vd);
+  // CHECK-LABEL: try-xvrdpic
+  // CHECK-UNCONSTRAINED: @llvm.nearbyint.v2f64(<2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.nearbyint.v2f64(<2 x double> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrdpic
+
+  vf = __builtin_vsx_xvrspip(vf);
+  // CHECK-LABEL: try-xvrspip
+  // CHECK-UNCONSTRAINED: @llvm.ceil.v4f32(<4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.ceil.v4f32(<4 x float> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrspip
+
+  vd = __builtin_vsx_xvrdpip(vd);
+  // CHECK-LABEL: try-xvrdpip
+  // CHECK-UNCONSTRAINED: @llvm.ceil.v2f64(<2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.ceil.v2f64(<2 x double> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrdpip
+
+  vf = __builtin_vsx_xvrspiz(vf);
+  // CHECK-LABEL: try-xvrspiz
+  // CHECK-UNCONSTRAINED: @llvm.trunc.v4f32(<4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.trunc.v4f32(<4 x float> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrspiz
+
+  vd = __builtin_vsx_xvrdpiz(vd);
+  // CHECK-LABEL: try-xvrdpiz
+  // CHECK-UNCONSTRAINED: @llvm.trunc.v2f64(<2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.trunc.v2f64(<2 x double> %{{.*}}, metadata !"fpexcept.strict")
+  // CHECK-ASM: xvrdpiz
+
+  vf = __builtin_vsx_xvmaddasp(vf, vf, vf);
+  // CHECK-LABEL: try-xvmaddasp
+  // CHECK-UNCONSTRAINED: @llvm.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvmaddasp
+
+  vd = __builtin_vsx_xvmaddadp(vd, vd, vd);
+  // CHECK-LABEL: try-xvmaddadp
+  // CHECK-UNCONSTRAINED: @llvm.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> %{{.*}})
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvmaddadp
+
+  vf = __builtin_vsx_xvnmaddasp(vf, vf, vf);
+  // CHECK-LABEL: try-xvnmaddasp
+  // CHECK-UNCONSTRAINED: [[RESULT:%[^ ]+]] = call <4 x float> @llvm.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}})
+  // CHECK-UNCONSTRAINED: fneg <4 x float> [[RESULT]]
+  // CHECK-CONSTRAINED: [[RESULT:%[^ ]+]] = call <4 x float> @llvm.experimental.constrained.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-CONSTRAINED: fneg <4 x float> [[RESULT]]
+  // NOT-FIXME-CHECK: xvnmaddasp
+  // FIXME-CHECK: xvmaddasp
+  // FIXME-CHECK: xvnegsp
+
+  vd = __builtin_vsx_xvnmaddadp(vd, vd, vd);
+  // CHECK-LABEL: try-xvnmaddadp
+  // CHECK-UNCONSTRAINED: [[RESULT:%[^ ]+]] = call <2 x double> @llvm.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> %{{.*}})
+  // CHECK-UNCONSTRAINED: fneg <2 x double> [[RESULT]]
+  // CHECK-CONSTRAINED: [[RESULT:%[^ ]+]] = call <2 x double> @llvm.experimental.constrained.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> %{{.*}}, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-CONSTRAINED: fneg <2 x double> [[RESULT]]
+  // CHECK-ASM: xvnmaddadp
+
+  vf = __builtin_vsx_xvmsubasp(vf, vf, vf);
+  // CHECK-LABEL: try-xvmsubasp
+  // CHECK-UNCONSTRAINED: [[RESULT:%[^ ]+]] = fneg <4 x float> %{{.*}}
+  // CHECK-UNCONSTRAINED: @llvm.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> [[RESULT]])
+  // CHECK-CONSTRAINED: [[RESULT:%[^ ]+]] = fneg <4 x float> %{{.*}}
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> [[RESULT]], metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM: xvmsubasp
+
+  vd = __builtin_vsx_xvmsubadp(vd, vd, vd);
+  // CHECK-LABEL: try-xvmsubadp
+  // CHECK-UNCONSTRAINED: [[RESULT:%[^ ]+]] = fneg <2 x double> %{{.*}}
+  // CHECK-UNCONSTRAINED: @llvm.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> [[RESULT]])
+  // CHECK-CONSTRAINED: [[RESULT:%[^ ]+]] = fneg <2 x double> %{{.*}}
+  // CHECK-CONSTRAINED: @llvm.experimental.constrained.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> [[RESULT]], metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-ASM:  xvmsubadp
+
+  vf = __builtin_vsx_xvnmsubasp(vf, vf, vf);
+  // CHECK-LABEL: try-xvnmsubasp
+  // CHECK-UNCONSTRAINED: [[RESULT0:%[^ ]+]] = fneg <4 x float> %{{.*}}
+  // CHECK-UNCONSTRAINED: [[RESULT1:%[^ ]+]] = call <4 x float> @llvm.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> [[RESULT0]])
+  // CHECK-UNCONSTRAINED: fneg <4 x float> [[RESULT1]]
+  // CHECK-CONSTRAINED: [[RESULT0:%[^ ]+]] = fneg <4 x float> %{{.*}}
+  // CHECK-CONSTRAINED: [[RESULT1:%[^ ]+]] = call <4 x float> @llvm.experimental.constrained.fma.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> [[RESULT0]], metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-CONSTRAINED: fneg <4 x float> [[RESULT1]]
+  // CHECK-ASM: xvnmsubasp
+
+  vd = __builtin_vsx_xvnmsubadp(vd, vd, vd);
+  // CHECK-LABEL: try-xvnmsubadp
+  // CHECK-UNCONSTRAINED: [[RESULT0:%[^ ]+]] = fneg <2 x double> %{{.*}}
+  // CHECK-UNCONSTRAINED: [[RESULT1:%[^ ]+]] = call <2 x double> @llvm.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> [[RESULT0]])
+  // CHECK-UNCONSTRAINED: fneg <2 x double> [[RESULT1]]
+  // CHECK-CONSTRAINED: [[RESULT0:%[^ ]+]] = fneg <2 x double> %{{.*}}
+  // CHECK-CONSTRAINED: [[RESULT1:%[^ ]+]] = call <2 x double> @llvm.experimental.constrained.fma.v2f64(<2 x double> %{{.*}}, <2 x double> %{{.*}}, <2 x double> [[RESULT0]], metadata !"round.tonearest", metadata !"fpexcept.strict")
+  // CHECK-CONSTRAINED: fneg <2 x double> [[RESULT1]]
+  // CHECK-ASM: xvnmsubadp
+}


        


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