MIPS: fix build from IR files, nan2008 and FpAbi

[wzssyqa]

Summary

When we use llc or lld to compiler IR files, the features +nan2008 and +fpxx/+fp64 are not used.
Thus wrong format files are produced.

In IR files, the attributes are only set for function while not the whole compile units.
So we extract the attributes from the first function and use it for the whole unit.

isFPXXDefault: for o32, the FPXX should always be the default, no matter about the vendors.
Of course some distributions with FP64 default enabled should be listed explicit.
Let's add them in future if we know about one.

[MaskRay]

Is there a test ?

If we emit . module or .nan for all functions in a single build unit, [...]

.module

llvm/lib/Target/Mips/MipsAsmPrinter.h

66 ↗

(On Diff #483823)

Delete "isFirstFunction - " it's an obsoleted style of documentation.

[nathanchance]

Thanks for the fix! It does not appear to be enough though, I still see some of those errors in my build, although there are far fewer of them:

/tmp/syscall-69c080.s: Assembler messages:
/tmp/syscall-69c080.s:224: Error: .module is not permitted after generating code
clang-16: error: assembler command failed with exit code 1 (use -v to see invocation)
make[5]: *** [/home/nathan/cbl/src/linux/scripts/Makefile.build:250: arch/mips/kernel/syscall.o] Error 1

/tmp/traps-4cb796.s: Assembler messages:
/tmp/traps-4cb796.s:161: Error: .module is not permitted after generating code
clang-16: error: assembler command failed with exit code 1 (use -v to see invocation)
make[5]: *** [/home/nathan/cbl/src/linux/scripts/Makefile.build:250: arch/mips/kernel/traps.o] Error 1

/tmp/sys_ni-0c2210.s: Assembler messages:
/tmp/sys_ni-0c2210.s:538: Error: .module is not permitted after generating code
clang-16: error: assembler command failed with exit code 1 (use -v to see invocation)
make[4]: *** [/home/nathan/cbl/src/linux/scripts/Makefile.build:250: kernel/sys_ni.o] Error 1

/tmp/configs-c3d91c.s: Assembler messages:
/tmp/configs-c3d91c.s:134: Error: .module is not permitted after generating code
clang-16: error: assembler command failed with exit code 1 (use -v to see invocation)
make[4]: *** [/home/nathan/cbl/src/linux/scripts/Makefile.build:251: kernel/configs.o] Error 1

I can try to reduce something out if it would be useful, unless you see an immediate issue.

[nathanchance]

cvise spits out:

__asm__("       .previous                       \n");
void __attribute__set_raw_show_trace() {}

$ clang --target=mips-linux-gnu -fno-integrated-as -c -o /dev/null traps.i
/tmp/traps-0867c0.s: Assembler messages:
/tmp/traps-0867c0.s:23: Error: .module is not permitted after generating code
/tmp/traps-0867c0.s:26: Warning: .ent or .aent not in text section
/tmp/traps-0867c0.s:48: Warning: .end not in text section
clang-16: error: assembler command failed with exit code 1 (use -v to see invocation)

which appears to come from

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/mips/kernel/traps.c#n431

If this cannot be resolved by tomorrow, can the original patch be reverted and resubmitted with this fixed? This is breaking our and others' builds:

https://lore.kernel.org/CA+G9fYs=[e-mail]/

[wzssyqa]

@nathanchance can you have a try of this patch?

[MaskRay]

llvm/test/CodeGen/Mips/abiflags-2008-fp64.ll

2

Add ;; file-level comment what this test does.

[nathanchance]

This does not show any issues with any of the MIPS configurations that I build in the Linux kernel, thanks for fixing the problems I reported!

[wzssyqa]

ping

[MaskRay]

In D140270#4089857, @wzssyqa wrote:

ping

I don't know how to test this, so this will be up to @nathanchance ...
(Thanks for improving the mips port, though)

[nathanchance]

I tested this against the kernel and left my feedback above (no issues) so this can be merged.

[MaskRay]

Thanks!

[wzssyqa]

@MaskRay can you help to submit this patch?

clang/lib/Driver/ToolChains/Arch/Mips.cpp

bool mips::isFP64ADefault(const llvm::Triple &Triple, StringRef CPUName) {
   // Android MIPS32R6 defaults to FP64A.
   return llvm::StringSwitch<bool>(CPUName)
       .Case("mips32r6", true)
       .Default(false);
 }
 
 bool mips::isFPXXDefault(const llvm::Triple &Triple, StringRef CPUName,
                          StringRef ABIName, mips::FloatABI FloatABI) {
-  if (Triple.getVendor() != llvm::Triple::ImaginationTechnologies &&
-      Triple.getVendor() != llvm::Triple::MipsTechnologies &&
-      !Triple.isAndroid())
-    return false;
-
   if (ABIName != "32")
     return false;
 
   // FPXX shouldn't be used if either -msoft-float or -mfloat-abi=soft is
   // present.
   if (FloatABI == mips::FloatABI::Soft)
     return false;
 

clang/test/Driver/mips-as.c

 // RUN: %clang -target mips64-linux-gnu -mips64r6 -### \
 // RUN:   -no-integrated-as -fno-pic -c %s -fno-pic -mno-abicalls 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R6 %s
 // MIPS-ALIAS-64R6: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-mno-shared" "-EB"
 //
 // RUN: %clang -target mips-linux-gnu -mno-mips16 -mips16 -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-16 %s
-// MIPS-16: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mips16"
+// MIPS-16: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mfpxx" "-mips16"
 //
 // RUN: %clang -target mips-linux-gnu -mips16 -mno-mips16 -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-N16 %s
 // MIPS-N16: as{{(.exe)?}}"
 // MIPS-N16: -no-mips16
 //
 // RUN: %clang -target mips-linux-gnu -mno-micromips -mmicromips -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-MICRO %s
-// MIPS-MICRO: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mmicromips"
+// MIPS-MICRO: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mfpxx" "-mmicromips"
 //
 // RUN: %clang -target mips-linux-gnu -mmicromips -mno-micromips -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-NMICRO %s
 // MIPS-NMICRO: as{{(.exe)?}}"
 // MIPS-NMICRO-NOT: {{[A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-mmicromips"
 //
 // RUN: %clang -target mips-linux-gnu -mno-dsp -mdsp -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-DSP %s
-// MIPS-DSP: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mdsp"
+// MIPS-DSP: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mfpxx" "-mdsp"
 //
 // RUN: %clang -target mips-linux-gnu -mdsp -mno-dsp -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-NDSP %s
 // MIPS-NDSP: as{{(.exe)?}}"
 // MIPS-NDSP-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-mdsp"
 //
 // RUN: %clang -target mips-linux-gnu -mno-dspr2 -mdspr2 -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-DSPR2 %s
-// MIPS-DSPR2: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mdspr2"
+// MIPS-DSPR2: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mfpxx" "-mdspr2"
 //
 // RUN: %clang -target mips-linux-gnu -mdspr2 -mno-dspr2 -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-NDSPR2 %s
 // MIPS-NDSPR2: as{{(.exe)?}}"
 // MIPS-NDSPR2-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-mdspr2"
 //
 // RUN: %clang -target mips-linux-gnu -mnan=legacy -mnan=2008 -### \

 // RUN: %clang -target mips-linux-gnu -mfpxx -mfp32 -mfp64 -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-MFP64 %s
 // MIPS-MFP64: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mfp64"
 //
 // RUN: %clang -target mips-linux-gnu -mno-msa -mmsa -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-MSA %s
-// MIPS-MSA: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mmsa"
+// MIPS-MSA: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mfpxx" "-mmsa"
 //
 // RUN: %clang -target mips-linux-gnu -mmsa -mno-msa -### \
 // RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-NMSA %s
 // MIPS-NMSA: as{{(.exe)?}}"
 // MIPS-NMSA-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-mmsa"
 //
 // We've already tested MIPS32r2 and MIPS64r2 thoroughly. Do minimal tests on

clang/test/Driver/mips-integrated-as.s

 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-msa 2>&1 | \
 // RUN:   FileCheck -check-prefix=MSA-OFF %s
 // MSA-OFF: -cc1as
 // MSA-OFF: "-target-feature" "-msa"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
 // RUN:   FileCheck -check-prefix=FPXX-DEFAULT %s
 // FPXX-DEFAULT: -cc1as
-// FPXX-DEFAULT-NOT: "-target-feature" "+fpxx"
-// FPXX-DEFAULT-NOT: "-target-feature" "+nooddspreg"
+// FPXX-DEFAULT: "-target-feature" "+fpxx"
+// FPXX-DEFAULT: "-target-feature" "+nooddspreg"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfp32 2>&1 | \
 // RUN:   FileCheck -check-prefix=FP32 %s
 // FP32: -cc1as
 // FP32: "-target-feature" "-fp64"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfpxx 2>&1 | \
 // RUN:   FileCheck -check-prefix=FPXX %s
 // FPXX: -cc1as
 // FPXX: "-target-feature" "+fpxx"
 // FPXX: "-target-feature" "+nooddspreg"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfp64 2>&1 | \
 // RUN:   FileCheck -check-prefix=FP64 %s
 // FP64: -cc1as
 // FP64: "-target-feature" "+fp64"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
 // RUN:   FileCheck -check-prefix=ODDSPREG-DEFAULT %s
 // ODDSPREG-DEFAULT: -cc1as
-// ODDSPREG-DEFAULT-NOT: "-target-feature" "{{[+-]}}nooddspreg"
+// ODDSPREG-DEFAULT: "-target-feature" "+nooddspreg"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -modd-spreg 2>&1 | \
 // RUN:   FileCheck -check-prefix=ODDSPREG-ON %s
 // ODDSPREG-ON: -cc1as
 // ODDSPREG-ON: "-target-feature" "-nooddspreg"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-odd-spreg 2>&1 | \
 // RUN:   FileCheck -check-prefix=ODDSPREG-OFF %s

llvm/lib/Target/Mips/MipsAsmPrinter.cpp

 void MipsAsmPrinter::emitStartOfAsmFile(Module &M) {
   MipsTargetStreamer &TS = getTargetStreamer();
 
   // MipsTargetStreamer has an initialization order problem when emitting an
   // object file directly (see MipsTargetELFStreamer for full details). Work
   // around it by re-initializing the PIC state here.
   TS.setPic(OutContext.getObjectFileInfo()->isPositionIndependent());
 
+  // Try to get target-features from the first function.
+  StringRef FS = TM.getTargetFeatureString();
+  Module::iterator F = M.begin();
+  if (FS.empty() && M.size() && F->hasFnAttribute("target-features"))
+    FS = F->getFnAttribute("target-features").getValueAsString();
+
   // Compute MIPS architecture attributes based on the default subtarget
-  // that we'd have constructed. Module level directives aren't LTO
-  // clean anyhow.
+  // that we'd have constructed.
   // FIXME: For ifunc related functions we could iterate over and look
   // for a feature string that doesn't match the default one.
   const Triple &TT = TM.getTargetTriple();
   StringRef CPU = MIPS_MC::selectMipsCPU(TT, TM.getTargetCPU());
-  StringRef FS = TM.getTargetFeatureString();
   const MipsTargetMachine &MTM = static_cast<const MipsTargetMachine &>(TM);
   const MipsSubtarget STI(TT, CPU, FS, MTM.isLittleEndian(), MTM, std::nullopt);
 
   bool IsABICalls = STI.isABICalls();
   const MipsABIInfo &ABI = MTM.getABI();
   if (IsABICalls) {
     TS.emitDirectiveAbiCalls();
     // FIXME: This condition should be a lot more complicated that it is here.

llvm/test/CodeGen/Mips/abiflags-2008-fp64.ll

+;; When we compile object with "-flto", the info of "-mnan=2008"
+;; and "-mfp32/-mfpxx/-mfp64" will be missing in the result IR file.
+;; Thus the asm/obj files will have wrong format.
+;; With D140270 we extract these info from the first function,
+;; and set it for the whole compile unit.
+; RUN: llc %s -o - | FileCheck %s
+
+target triple = "mipsel-unknown-linux-gnu"
+
+define dso_local void @test() #0 {
+  ret void
+}
+
+attributes #0 = { "target-cpu"="mips32r2" "target-features"="+fp64,+mips32r2,+nan2008" }
+
+
+; CHECK: .nan    2008
+; CHECK: .module fp=64