[clang] 0175999 - [AMDGPU] Add options -mamdgpu-ieee -mno-amdgpu-ieee
Yaxun Liu via cfe-commits
cfe-commits at lists.llvm.org
Sat May 1 06:04:33 PDT 2021
Author: Yaxun (Sam) Liu
Date: 2021-05-01T09:02:55-04:00
New Revision: 0175999805cf05d91c8a127ebd8c9d54a640abe9
URL: https://github.com/llvm/llvm-project/commit/0175999805cf05d91c8a127ebd8c9d54a640abe9
DIFF: https://github.com/llvm/llvm-project/commit/0175999805cf05d91c8a127ebd8c9d54a640abe9.diff
LOG: [AMDGPU] Add options -mamdgpu-ieee -mno-amdgpu-ieee
AMDGPU backend need to know whether floating point opcodes that support exception
flag gathering quiet and propagate signaling NaN inputs per IEEE754-2008, which is
conveyed by a function attribute "amdgpu-ieee". "amdgpu-ieee"="false" turns this off.
Without this function attribute backend assumes it is on for compute functions.
-mamdgpu-ieee and -mno-amdgpu-ieee are added to Clang to control this function attribute.
By default it is on. -mno-amdgpu-ieee requires -fno-honor-nans or equivalent.
Reviewed by: Matt Arsenault
Differential Revision: https://reviews.llvm.org/D77013
Added:
clang/test/CodeGenOpenCL/amdgpu-ieee.cl
Modified:
clang/include/clang/Basic/CodeGenOptions.def
clang/include/clang/Basic/DiagnosticDriverKinds.td
clang/include/clang/Driver/Options.td
clang/lib/CodeGen/TargetInfo.cpp
clang/lib/Frontend/CompilerInvocation.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def
index d30dca5b18dab..e0bfcf6ef3e4c 100644
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -426,6 +426,11 @@ CODEGENOPT(PassByValueIsNoAlias, 1, 0)
/// according to the field declaring type width.
CODEGENOPT(AAPCSBitfieldWidth, 1, 1)
+/// Sets the IEEE bit in the expected default floating point mode register.
+/// Floating point opcodes that support exception flag gathering quiet and
+/// propagate signaling NaN inputs per IEEE 754-2008 (AMDGPU Only)
+CODEGENOPT(EmitIEEENaNCompliantInsts, 1, 1)
+
#undef CODEGENOPT
#undef ENUM_CODEGENOPT
#undef VALUE_CODEGENOPT
diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index a2ffe1378cb6d..1ae0df3633b35 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -129,6 +129,8 @@ def err_drv_invalid_Xopenmp_target_with_args : Error<
"invalid -Xopenmp-target argument: '%0', options requiring arguments are unsupported">;
def err_drv_argument_only_allowed_with : Error<
"invalid argument '%0' only allowed with '%1'">;
+def err_drv_amdgpu_ieee_without_no_honor_nans : Error<
+ "invalid argument '-mno-amdgpu-ieee' only allowed with relaxed NaN handling">;
def err_drv_argument_not_allowed_with : Error<
"invalid argument '%0' not allowed with '%1'">;
def err_drv_invalid_version_number : Error<
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 8c9033ded10b6..a8a7177c82cc9 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -3177,6 +3177,14 @@ def mexec_model_EQ : Joined<["-"], "mexec-model=">, Group<m_wasm_Features_Driver
Values<"command,reactor">,
HelpText<"Execution model (WebAssembly only)">;
+defm amdgpu_ieee : BoolOption<"m", "amdgpu-ieee",
+ CodeGenOpts<"EmitIEEENaNCompliantInsts">, DefaultTrue,
+ PosFlag<SetTrue, [], "Sets the IEEE bit in the expected default floating point "
+ " mode register. Floating point opcodes that support exception flag "
+ "gathering quiet and propagate signaling NaN inputs per IEEE 754-2008. "
+ "This option changes the ABI. (AMDGPU only)">,
+ NegFlag<SetFalse, [CC1Option]>>, Group<m_Group>;
+
def mcode_object_version_EQ : Joined<["-"], "mcode-object-version=">, Group<m_Group>,
HelpText<"Specify code object ABI version. Defaults to 3. (AMDGPU only)">,
MetaVarName<"<version>">, Values<"2,3,4">;
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 52dce97605ea9..9577b61ca6d00 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -9166,6 +9166,9 @@ void AMDGPUTargetCodeGenInfo::setTargetAttributes(
if (M.getContext().getTargetInfo().allowAMDGPUUnsafeFPAtomics())
F->addFnAttr("amdgpu-unsafe-fp-atomics", "true");
+
+ if (!getABIInfo().getCodeGenOpts().EmitIEEENaNCompliantInsts)
+ F->addFnAttr("amdgpu-ieee", "false");
}
unsigned AMDGPUTargetCodeGenInfo::getOpenCLKernelCallingConv() const {
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 2578c8cc0b952..b3e1e06bf8a25 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1944,6 +1944,11 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
else if (Args.hasArg(options::OPT_fno_finite_loops))
Opts.FiniteLoops = CodeGenOptions::FiniteLoopsKind::Never;
+ Opts.EmitIEEENaNCompliantInsts =
+ Args.hasFlag(options::OPT_mamdgpu_ieee, options::OPT_mno_amdgpu_ieee);
+ if (!Opts.EmitIEEENaNCompliantInsts && !LangOptsRef.NoHonorNaNs)
+ Diags.Report(diag::err_drv_amdgpu_ieee_without_no_honor_nans);
+
return Diags.getNumErrors() == NumErrorsBefore;
}
diff --git a/clang/test/CodeGenOpenCL/amdgpu-ieee.cl b/clang/test/CodeGenOpenCL/amdgpu-ieee.cl
new file mode 100644
index 0000000000000..0a7b0d4f494ef
--- /dev/null
+++ b/clang/test/CodeGenOpenCL/amdgpu-ieee.cl
@@ -0,0 +1,47 @@
+// REQUIRES: amdgpu-registered-target
+//
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -O0 -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefixes=COMMON,ON %s
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -O0 -emit-llvm -o - %s \
+// RUN: -mno-amdgpu-ieee -menable-no-nans \
+// RUN: | FileCheck -check-prefixes=COMMON,OFF %s
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -O0 -emit-llvm -o - %s \
+// RUN: -mno-amdgpu-ieee -cl-fast-relaxed-math \
+// RUN: | FileCheck -check-prefixes=COMMON,OFF %s
+
+// Check AMDGCN ISA generation.
+
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -O3 -S -o - %s \
+// RUN: | FileCheck -check-prefixes=ISA-ON %s
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -O3 -S -o - %s \
+// RUN: -mno-amdgpu-ieee -menable-no-nans \
+// RUN: | FileCheck -check-prefixes=ISA-OFF %s
+
+// Check diagnostics when using -mno-amdgpu-ieee without NoHonorNaNs.
+
+// RUN: not %clang_cc1 -triple amdgcn-amd-amdhsa -O0 -emit-llvm -o - %s \
+// RUN: -mno-amdgpu-ieee 2>&1 | FileCheck -check-prefixes=DIAG %s
+
+// COMMON: define{{.*}} amdgpu_kernel void @kern{{.*}} [[ATTRS1:#[0-9]+]]
+// ISA-ON: v_mul_f32_e64 v{{[0-9]+}}, 1.0, s{{[0-9]+}}
+// ISA-ON: v_mul_f32_e64 v{{[0-9]+}}, 1.0, s{{[0-9]+}}
+// ISA-ON: v_min_f32_e32
+// ISA-ON: ; IeeeMode: 1
+// ISA-OFF-NOT: v_mul_f32_e64 v{{[0-9]+}}, 1.0, s{{[0-9]+}}
+// ISA-OFF-NOT: v_mul_f32_e64 v{{[0-9]+}}, 1.0, s{{[0-9]+}}
+// ISA-OFF: v_min_f32_e32
+// ISA-OFF: ; IeeeMode: 0
+kernel void kern(global float *x, float y, float z) {
+ *x = __builtin_fmin(y, z);
+}
+
+// COMMON: define{{.*}}void @fun() [[ATTRS2:#[0-9]+]]
+void fun() {
+}
+
+// ON-NOT: attributes [[ATTRS1]] = {{.*}} "amdgpu-ieee"
+// OFF: attributes [[ATTRS1]] = {{.*}} "amdgpu-ieee"="false"{{.*}}"no-nans-fp-math"="true"{{.*}}"no-trapping-math"="true"
+// ON-NOT: attributes [[ATTRS2]] = {{.*}} "amdgpu-ieee"
+// OFF: attributes [[ATTRS2]] = {{.*}} "amdgpu-ieee"="false"{{.*}}"no-nans-fp-math"="true"{{.*}}"no-trapping-math"="true"
+
+// DIAG: invalid argument '-mno-amdgpu-ieee' only allowed with relaxed NaN handling
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