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clang/AMDGPU: Fix accidental behavior change for __builtin_amdgcn_ldexph #66340

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Merged
merged 1 commit into from
Sep 14, 2023
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clang/AMDGPU: Fix accidental behavior change for __builtin_amdgcn_ldexph #66340

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12 changes: 10 additions & 2 deletions clang/lib/CodeGen/CGBuiltin.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -17392,14 +17392,22 @@ Value *CodeGenFunction::EmitAMDGPUBuiltinExpr(unsigned BuiltinID,
case AMDGPU::BI__builtin_amdgcn_log_clampf:
return emitUnaryBuiltin(*this, E, Intrinsic::amdgcn_log_clamp);
case AMDGPU::BI__builtin_amdgcn_ldexp:
case AMDGPU::BI__builtin_amdgcn_ldexpf:
case AMDGPU::BI__builtin_amdgcn_ldexph: {
case AMDGPU::BI__builtin_amdgcn_ldexpf: {
llvm::Value *Src0 = EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = EmitScalarExpr(E->getArg(1));
llvm::Function *F =
CGM.getIntrinsic(Intrinsic::ldexp, {Src0->getType(), Src1->getType()});
return Builder.CreateCall(F, {Src0, Src1});
}
case AMDGPU::BI__builtin_amdgcn_ldexph: {
// The raw instruction has a different behavior for out of bounds exponent
// values (implicit truncation instead of saturate to short_min/short_max).
llvm::Value *Src0 = EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = EmitScalarExpr(E->getArg(1));
llvm::Function *F =
CGM.getIntrinsic(Intrinsic::ldexp, {Src0->getType(), Int16Ty});
return Builder.CreateCall(F, {Src0, Builder.CreateTrunc(Src1, Int16Ty)});
}
case AMDGPU::BI__builtin_amdgcn_frexp_mant:
case AMDGPU::BI__builtin_amdgcn_frexp_mantf:
case AMDGPU::BI__builtin_amdgcn_frexp_manth:
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3 changes: 2 additions & 1 deletion clang/test/CodeGenOpenCL/builtins-amdgcn-vi.cl
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Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,8 @@ void test_cos_f16(global half* out, half a)
}

// CHECK-LABEL: @test_ldexp_f16
// CHECK: call half @llvm.ldexp.f16.i32
// CHECK: [[TRUNC:%[0-9a-z]+]] = trunc i32
// CHECK: call half @llvm.ldexp.f16.i16(half %a, i16 [[TRUNC]])
void test_ldexp_f16(global half* out, half a, int b)
{
*out = __builtin_amdgcn_ldexph(a, b);
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