[X86] Add basic support for -mtune command line option in clang

[craig.topper]

Summary

Building on the backend support from D85165. This parses the command line option in the driver, passes it on to CC1 and adds a function attribute.

Still need to support tune on the target attribute.
Need to use "generic" as the tuning by default. But need to change generic in the backend first.
Need to set tune if march is specified and mtune isn't.
May need to disable getHostCPUName's ability to guess CPU name from features when it doesn't have a family/model match for mtune=native. That's what gcc appears to do.

[craig.topper]

Ping

[erichkeane]

1 comment, otherwise seems alright to me.

clang/lib/CodeGen/CodeGenModule.cpp

1752

Does this lead to a situation in 'attribute-target' where we have a 'tune' setting to a processor that is 'before' the 'TargetCPU'? Should this enforce some sort of hierarchy to make sure we only do it if it is 'newer' (read, more feature rich) than the target?

[craig.topper]

clang/lib/CodeGen/CodeGenModule.cpp

1752

TuneCPU is only supposed to control microarchitectural things like should i prefer an "ADD 1" over "INC" instruction. Or should I use more immediate controlled shuffles over a single variable controlled shuffle. As such that things we get from tune don't have a straightforward relationship with architectural features.

[erichkeane]

clang/lib/CodeGen/CodeGenModule.cpp

1752

My concern is more. Say:

TargetCPU == "nahalem"

Does it make sense for
TuneCPU == "pentium"?

It would seem to me that is pretty nonsensical. I've definitely seen the reverse (in within x86_64 at least, where Tune is newer than Target), but tuning for an older CPU seems like nonsense.

[craig.topper]

clang/lib/CodeGen/CodeGenModule.cpp

1752

From a behavior standpoint, its not any different than what this does today

-march=pentium -msse4.2 -mpopcnt -mfxsr <other nehalem features>

I don't think gcc enforces any ordering.

[efriedma]

LGTM with one minor comment

clang/test/Misc/target-invalid-cpu-note.c

54

Should we have a test for tune-cpu for some non-x86 target? Or are we happy to just assume this works correctly because we already have coverage for target-cpu?

[craig.topper]

clang/test/Misc/target-invalid-cpu-note.c

54

I copied the AARCH64 test above an added a -tune-cpu version of it. That will be included with my commit

[phosek]

This seems to have broken our Mac builders with the following error:

-- Testing: 25226 tests, 24 workers --
Testing:  0.. 10.. 20.
FAIL: Clang :: Frontend/ast-main.c (6834 of 25226)
******************** TEST 'Clang :: Frontend/ast-main.c' FAILED ********************
Script:
--
: 'RUN: at line 1';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp1.ll -x c - < /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.c
: 'RUN: at line 2';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-ast -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp.ast /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.c
: 'RUN: at line 3';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp2.ll -x ast - < /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp.ast
: 'RUN: at line 4';   diff /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp1.ll /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp2.ll
--
Exit Code: 1

Command Output (stdout):
--
14c14
< attributes #0 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
---
> attributes #0 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

--

********************
Testing:  0.. 10.. 20.
FAIL: Clang :: Frontend/ast-main.cpp (6835 of 25226)
******************** TEST 'Clang :: Frontend/ast-main.cpp' FAILED ********************
Script:
--
: 'RUN: at line 1';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp1.ll -x c++ - < /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp
: 'RUN: at line 2';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -fno-delayed-template-parsing -emit-ast -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp.ast /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp
: 'RUN: at line 3';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp2.ll -x ast - < /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp.ast
: 'RUN: at line 4';   diff /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp1.ll /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp2.ll
--
Exit Code: 1

Command Output (stdout):
--
37,39c37,39
< attributes #0 = { noinline optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
< attributes #1 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
< attributes #2 = { noinline norecurse nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
---
> attributes #0 = { noinline optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
> attributes #1 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
> attributes #2 = { noinline norecurse nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

--
Command Output (stderr):
--
<stdin>:14:1: warning: non-void function does not return a value [-Wreturn-type]
}
^
<stdin>:17:14: note: in instantiation of member function 'S<int>::mf' requested here
    S<int>().mf();
             ^
1 warning generated.
/b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp:14:1: warning: non-void function does not return a value [-Wreturn-type]
}
^
/b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp:17:14: note: in instantiation of member function 'S<int>::mf' requested here
    S<int>().mf();
             ^
1 warning generated.

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
********************
Failed Tests (2):
  Clang :: Frontend/ast-main.c
  Clang :: Frontend/ast-main.cpp


Testing Time: 225.68s
  Unsupported      :   564
  Passed           : 24636
  Expectedly Failed:    24
  Failed           :     2

Specifically, the tune-cpu attribute seems to be missing on Darwin. Would it be possible to take a look?

[craig.topper]

In D85384#2225434, @phosek wrote:

This seems to have broken our Mac builders with the following error:

-- Testing: 25226 tests, 24 workers --
Testing:  0.. 10.. 20.
FAIL: Clang :: Frontend/ast-main.c (6834 of 25226)
******************** TEST 'Clang :: Frontend/ast-main.c' FAILED ********************
Script:
--
: 'RUN: at line 1';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp1.ll -x c - < /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.c
: 'RUN: at line 2';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-ast -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp.ast /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.c
: 'RUN: at line 3';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp2.ll -x ast - < /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp.ast
: 'RUN: at line 4';   diff /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp1.ll /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.c.tmp2.ll
--
Exit Code: 1

Command Output (stdout):
--
14c14
< attributes #0 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
---
> attributes #0 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

--

********************
Testing:  0.. 10.. 20.
FAIL: Clang :: Frontend/ast-main.cpp (6835 of 25226)
******************** TEST 'Clang :: Frontend/ast-main.cpp' FAILED ********************
Script:
--
: 'RUN: at line 1';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp1.ll -x c++ - < /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp
: 'RUN: at line 2';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -fno-delayed-template-parsing -emit-ast -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp.ast /b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp
: 'RUN: at line 3';   env SDKROOT="/" /b/s/w/ir/k/staging/llvm_build/bin/clang -emit-llvm -S -o /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp2.ll -x ast - < /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp.ast
: 'RUN: at line 4';   diff /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp1.ll /b/s/w/ir/k/staging/llvm_build/tools/clang/test/Frontend/Output/ast-main.cpp.tmp2.ll
--
Exit Code: 1

Command Output (stdout):
--
37,39c37,39
< attributes #0 = { noinline optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
< attributes #1 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
< attributes #2 = { noinline norecurse nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
---
> attributes #0 = { noinline optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
> attributes #1 = { noinline nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
> attributes #2 = { noinline norecurse nounwind optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

--
Command Output (stderr):
--
<stdin>:14:1: warning: non-void function does not return a value [-Wreturn-type]
}
^
<stdin>:17:14: note: in instantiation of member function 'S<int>::mf' requested here
    S<int>().mf();
             ^
1 warning generated.
/b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp:14:1: warning: non-void function does not return a value [-Wreturn-type]
}
^
/b/s/w/ir/k/llvm-project/clang/test/Frontend/ast-main.cpp:17:14: note: in instantiation of member function 'S<int>::mf' requested here
    S<int>().mf();
             ^
1 warning generated.

--

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
********************
Failed Tests (2):
  Clang :: Frontend/ast-main.c
  Clang :: Frontend/ast-main.cpp


Testing Time: 225.68s
  Unsupported      :   564
  Passed           : 24636
  Expectedly Failed:    24
  Failed           :     2

Specifically, the tune-cpu attribute seems to be missing on Darwin. Would it be possible to take a look?

I suspect this is somehow related to the very old code in lib/Driver/ToolChains/Darwin.cpp that forces a -mtune=core2 into the command line. But I'm not clear yet why that code is there. @ddunbar looks like you added that code in 2009? Can you shed any light on what its for?

[echristo]

This would be because at that point the default cpu was that and it
probably had something to do with fallbacks.

At this point it can be changed I imagine to whatever makes sense.

[craig.topper]

In D85384#2225459, @echristo wrote:

This would be because at that point the default cpu was that and it
probably had something to do with fallbacks.

At this point it can be changed I imagine to whatever makes sense.

The issue seems to be that its somehow only being applied to one set of command lines. And the IR from the two sets of command lines are being differed. So I don't think there's any value that makes sense. Its existence is causing the diff somehow.

[aeubanks]

This doesn't work with -mtune=generic (https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html), can gcc compatibility be added?

(https://crbug.com/1119448)

$ cat /tmp/a.c
int main(){}
$ ./build/bin/clang /tmp/a.c -o /dev/null -mtune=generic
error: unknown target CPU 'generic'
note: valid target CPU values are: nocona, core2, penryn, bonnell, atom, silvermont, slm, goldmont, goldmont-plus, tremont, nehalem, corei7, westmere, sandybridge, corei7-avx, ivybridge, core-avx-i, haswell, core-avx2, broadwell, skylake, skylake-avx512, skx, cascadelake, cooperlake, cannonlake, icelake-client, icelake-server, tigerlake, knl, knm, k8, athlon64, athlon-fx, opteron, k8-sse3, athlon64-sse3, opteron-sse3, amdfam10, barcelona, btver1, btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2, x86-64

[craig.topper]

In D85384#2226842, @aeubanks wrote:

This doesn't work with -mtune=generic (https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html), can gcc compatibility be added?

(https://crbug.com/1119448)

$ cat /tmp/a.c
int main(){}
$ ./build/bin/clang /tmp/a.c -o /dev/null -mtune=generic
error: unknown target CPU 'generic'
note: valid target CPU values are: nocona, core2, penryn, bonnell, atom, silvermont, slm, goldmont, goldmont-plus, tremont, nehalem, corei7, westmere, sandybridge, corei7-avx, ivybridge, core-avx-i, haswell, core-avx2, broadwell, skylake, skylake-avx512, skx, cascadelake, cooperlake, cannonlake, icelake-client, icelake-server, tigerlake, knl, knm, k8, athlon64, athlon-fx, opteron, k8-sse3, athlon64-sse3, opteron-sse3, amdfam10, barcelona, btver1, btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2, x86-64

I was planning to do work supporting that as one of my next patches. But didn't think about the fact that people would already doing it since the option was being ignored. I'll put in a quick fix.

[aeubanks]

In D85384#2226866, @craig.topper wrote:

In D85384#2226842, @aeubanks wrote:

This doesn't work with -mtune=generic (https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html), can gcc compatibility be added?

(https://crbug.com/1119448)

$ cat /tmp/a.c
int main(){}
$ ./build/bin/clang /tmp/a.c -o /dev/null -mtune=generic
error: unknown target CPU 'generic'
note: valid target CPU values are: nocona, core2, penryn, bonnell, atom, silvermont, slm, goldmont, goldmont-plus, tremont, nehalem, corei7, westmere, sandybridge, corei7-avx, ivybridge, core-avx-i, haswell, core-avx2, broadwell, skylake, skylake-avx512, skx, cascadelake, cooperlake, cannonlake, icelake-client, icelake-server, tigerlake, knl, knm, k8, athlon64, athlon-fx, opteron, k8-sse3, athlon64-sse3, opteron-sse3, amdfam10, barcelona, btver1, btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2, x86-64

I was planning to do work supporting that as one of my next patches. But didn't think about the fact that people would already doing it since the option was being ignored. I'll put in a quick fix.

Thanks!
There may be codebases trying to compile under both gcc and clang. Or remnants from gcc days?

clang/include/clang/Basic/TargetOptions.h

public:
 
   /// When compiling for the device side, contains the triple used to compile
   /// for the host.
   std::string HostTriple;
 
   /// If given, the name of the target CPU to generate code for.
   std::string CPU;
 
+  /// If given, the name of the target CPU to tune code for.
+  std::string TuneCPU;
+
   /// If given, the unit to use for floating point math.
   std::string FPMath;
 
   /// If given, the name of the target ABI to use.
   std::string ABI;
 
   /// The EABI version to use
   llvm::EABI EABIVersion;

clang/include/clang/Driver/Options.td

def mno_relax_pic_calls : Flag<["-"], "mno-relax-pic-calls">,
   HelpText<"Do not produce relaxation hints for linkers to try optimizing PIC "
            "call sequences into direct calls (MIPS only)">, Flags<[HelpHidden]>;
 def mglibc : Flag<["-"], "mglibc">, Group<m_libc_Group>, Flags<[HelpHidden]>;
 def muclibc : Flag<["-"], "muclibc">, Group<m_libc_Group>, Flags<[HelpHidden]>;
 def module_file_info : Flag<["-"], "module-file-info">, Flags<[DriverOption,CC1Option]>, Group<Action_Group>,
   HelpText<"Provide information about a particular module file">;
 def mthumb : Flag<["-"], "mthumb">, Group<m_Group>;
 def mtune_EQ : Joined<["-"], "mtune=">, Group<m_Group>,
-  HelpText<"Accepted for compatibility with GCC. Currently has no effect.">;
+  HelpText<"Only supported on X86. Otherwise accepted for compatibility with GCC.">;
 def multi__module : Flag<["-"], "multi_module">;
 def multiply__defined__unused : Separate<["-"], "multiply_defined_unused">;
 def multiply__defined : Separate<["-"], "multiply_defined">;
 def mwarn_nonportable_cfstrings : Flag<["-"], "mwarn-nonportable-cfstrings">, Group<m_Group>;
 def no_canonical_prefixes : Flag<["-"], "no-canonical-prefixes">, Flags<[HelpHidden, CoreOption]>,
   HelpText<"Use relative instead of canonical paths">;
 def no_cpp_precomp : Flag<["-"], "no-cpp-precomp">, Group<clang_ignored_f_Group>;
 def no_integrated_cpp : Flag<["-", "--"], "no-integrated-cpp">, Flags<[DriverOption]>;

 //===----------------------------------------------------------------------===//
 // Target Options
 //===----------------------------------------------------------------------===//
 
 let Flags = [CC1Option, CC1AsOption, NoDriverOption] in {
 
 def target_cpu : Separate<["-"], "target-cpu">,
   HelpText<"Target a specific cpu type">;
+def tune_cpu : Separate<["-"], "tune-cpu">,
+  HelpText<"Tune for a specific cpu type">;
 def target_feature : Separate<["-"], "target-feature">,
   HelpText<"Target specific attributes">;
 def triple : Separate<["-"], "triple">,
   HelpText<"Specify target triple (e.g. i686-apple-darwin9)">,
   MarshallingInfoString<"TargetOpts->Triple", "llvm::Triple::normalize(llvm::sys::getDefaultTargetTriple())", "std::string">,
   AlwaysEmit, Normalizer<"normalizeTriple">, DenormalizeString;
 def target_abi : Separate<["-"], "target-abi">,
   HelpText<"Target a particular ABI type">;

clang/lib/Basic/Targets.cpp

if (!Opts->CPU.empty() && !Target->setCPU(Opts->CPU)) {
     Diags.Report(diag::err_target_unknown_cpu) << Opts->CPU;
     SmallVector<StringRef, 32> ValidList;
     Target->fillValidCPUList(ValidList);
     if (!ValidList.empty())
       Diags.Report(diag::note_valid_options) << llvm::join(ValidList, ", ");
     return nullptr;
   }
 
+  // Check the TuneCPU name if specified.
+  if (!Opts->TuneCPU.empty() && !Target->isValidCPUName(Opts->TuneCPU)) {
+    Diags.Report(diag::err_target_unknown_cpu) << Opts->TuneCPU;
+    SmallVector<StringRef, 32> ValidList;
+    Target->fillValidCPUList(ValidList);
+    if (!ValidList.empty())
+      Diags.Report(diag::note_valid_options) << llvm::join(ValidList, ", ");
+    return nullptr;
+  }
+
   // Set the target ABI if specified.
   if (!Opts->ABI.empty() && !Target->setABI(Opts->ABI)) {
     Diags.Report(diag::err_target_unknown_abi) << Opts->ABI;
     return nullptr;
   }
 
   // Set the fp math unit.
   if (!Opts->FPMath.empty() && !Target->setFPMath(Opts->FPMath)) {

clang/lib/CodeGen/CodeGenModule.cpp

 }
 
 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
                                                 llvm::AttrBuilder &Attrs) {
   // Add target-cpu and target-features attributes to functions. If
   // we have a decl for the function and it has a target attribute then
   // parse that and add it to the feature set.
   StringRef TargetCPU = getTarget().getTargetOpts().CPU;
+  StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
   std::vector<std::string> Features;
   const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
   FD = FD ? FD->getMostRecentDecl() : FD;
   const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
   const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
   bool AddedAttr = false;
   if (TD || SD) {
     llvm::StringMap<bool> FeatureMap;
if (TD || SD) {
     // function.
     Features = getTarget().getTargetOpts().Features;
   }
 
   if (TargetCPU != "") {
     Attrs.addAttribute("target-cpu", TargetCPU);
     AddedAttr = true;
   }
+  if (TuneCPU != "") {
+    Attrs.addAttribute("tune-cpu", TuneCPU);
+    AddedAttr = true;
+  }
   if (!Features.empty()) {
     llvm::sort(Features);
     Attrs.addAttribute("target-features", llvm::join(Features, ","));
     AddedAttr = true;
   }
 
   return AddedAttr;
 }

clang/lib/Driver/ToolChains/Clang.cpp

 #include "clang/Driver/XRayArgs.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/CodeGen.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Compression.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Host.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
 #include "llvm/Support/TargetParser.h"
 #include "llvm/Support/YAMLParser.h"
 
 #ifdef LLVM_ON_UNIX
 #include <unistd.h> // For getuid().
 #endif
void Clang::AddX86TargetArgs(const ArgList &Args,
   }
 
   // Set flags to support MCU ABI.
   if (Args.hasFlag(options::OPT_miamcu, options::OPT_mno_iamcu, false)) {
     CmdArgs.push_back("-mfloat-abi");
     CmdArgs.push_back("soft");
     CmdArgs.push_back("-mstack-alignment=4");
   }
+
+  // Handle -mtune.
+  // FIXME: We should default to "generic" unless -march is set to match gcc.
+  if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_mtune_EQ)) {
+    StringRef Name = A->getValue();
+
+    if (Name == "native")
+      Name = llvm::sys::getHostCPUName();
+
+    CmdArgs.push_back("-tune-cpu");
+    CmdArgs.push_back(Args.MakeArgString(Name));
+  }
 }
 
 void Clang::AddHexagonTargetArgs(const ArgList &Args,
                                  ArgStringList &CmdArgs) const {
   CmdArgs.push_back("-mqdsp6-compat");
   CmdArgs.push_back("-Wreturn-type");
 
   if (auto G = toolchains::HexagonToolChain::getSmallDataThreshold(Args)) {

clang/lib/Frontend/CompilerInvocation.cpp

llvm::EABI EABIVersion = llvm::StringSwitch<llvm::EABI>(Value)
                                  .Default(llvm::EABI::Unknown);
     if (EABIVersion == llvm::EABI::Unknown)
       Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args)
                                                 << Value;
     else
       Opts.EABIVersion = EABIVersion;
   }
   Opts.CPU = std::string(Args.getLastArgValue(OPT_target_cpu));
+  Opts.TuneCPU = std::string(Args.getLastArgValue(OPT_tune_cpu));
   Opts.FPMath = std::string(Args.getLastArgValue(OPT_mfpmath));
   Opts.FeaturesAsWritten = Args.getAllArgValues(OPT_target_feature);
   Opts.LinkerVersion =
       std::string(Args.getLastArgValue(OPT_target_linker_version));
   Opts.OpenCLExtensionsAsWritten = Args.getAllArgValues(OPT_cl_ext_EQ);
   Opts.ForceEnableInt128 = Args.hasArg(OPT_fforce_enable_int128);
   Opts.NVPTXUseShortPointers = Args.hasFlag(
       options::OPT_fcuda_short_ptr, options::OPT_fno_cuda_short_ptr, false);

clang/test/Misc/target-invalid-cpu-note.c

 // RUN: not %clang_cc1 -triple armv5--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix ARM
 // ARM: error: unknown target CPU 'not-a-cpu'
 // ARM: note: valid target CPU values are:
 // ARM-SAME: arm2
 
 // RUN: not %clang_cc1 -triple arm64--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix AARCH64
 // AARCH64: error: unknown target CPU 'not-a-cpu'
 // AARCH64: note: valid target CPU values are:
 // AARCH64-SAME: cortex-a35,
 
+// RUN: not %clang_cc1 -triple arm64--- -tune-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix TUNE_AARCH64
+// TUNE_AARCH64: error: unknown target CPU 'not-a-cpu'
+// TUNE_AARCH64: note: valid target CPU values are:
+// TUNE_AARCH64-SAME: cortex-a35,
+
 // RUN: not %clang_cc1 -triple i386--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix X86
 // X86: error: unknown target CPU 'not-a-cpu'
 // X86: note: valid target CPU values are: i386, i486, winchip-c6, winchip2, c3,
 // X86-SAME: i586, pentium, pentium-mmx, pentiumpro, i686, pentium2, pentium3,
 // X86-SAME: pentium3m, pentium-m, c3-2, yonah, pentium4, pentium4m, prescott,
 // X86-SAME: nocona, core2, penryn, bonnell, atom, silvermont, slm, goldmont, goldmont-plus, tremont,
 // X86-SAME: nehalem, corei7, westmere, sandybridge, corei7-avx, ivybridge,
 // X86-SAME: core-avx-i, haswell, core-avx2, broadwell, skylake, skylake-avx512,
 // X86-SAME: skx, cascadelake, cooperlake, cannonlake, icelake-client, icelake-server, tigerlake, knl, knm, lakemont, k6, k6-2, k6-3,
 // X86-SAME: athlon, athlon-tbird, athlon-xp, athlon-mp, athlon-4, k8, athlon64,
 // X86-SAME: athlon-fx, opteron, k8-sse3, athlon64-sse3, opteron-sse3, amdfam10,
 // X86-SAME: barcelona, btver1, btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2,
 // X86-SAME: x86-64, geode
 
 // RUN: not %clang_cc1 -triple x86_64--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix X86_64
 // X86_64: error: unknown target CPU 'not-a-cpu'
 // X86_64: note: valid target CPU values are: nocona, core2, penryn, bonnell,
 // X86_64-SAME: atom, silvermont, slm, goldmont, goldmont-plus, tremont, nehalem, corei7, westmere,
 // X86_64-SAME: sandybridge, corei7-avx, ivybridge, core-avx-i, haswell,
 // X86_64-SAME: core-avx2, broadwell, skylake, skylake-avx512, skx, cascadelake, cooperlake, cannonlake,
 // X86_64-SAME: icelake-client, icelake-server, tigerlake, knl, knm, k8, athlon64, athlon-fx, opteron, k8-sse3,
 // X86_64-SAME: athlon64-sse3, opteron-sse3, amdfam10, barcelona, btver1,
 // X86_64-SAME: btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2, x86-64
 
+// RUN: not %clang_cc1 -triple i386--- -tune-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix TUNE_X86
+// TUNE_X86: error: unknown target CPU 'not-a-cpu'
+// TUNE_X86: note: valid target CPU values are: i386, i486, winchip-c6, winchip2, c3,
+// TUNE_X86-SAME: i586, pentium, pentium-mmx, pentiumpro, i686, pentium2, pentium3,
+// TUNE_X86-SAME: pentium3m, pentium-m, c3-2, yonah, pentium4, pentium4m, prescott,
+// TUNE_X86-SAME: nocona, core2, penryn, bonnell, atom, silvermont, slm, goldmont, goldmont-plus, tremont,
+// TUNE_X86-SAME: nehalem, corei7, westmere, sandybridge, corei7-avx, ivybridge,
+// TUNE_X86-SAME: core-avx-i, haswell, core-avx2, broadwell, skylake, skylake-avx512,
+// TUNE_X86-SAME: skx, cascadelake, cooperlake, cannonlake, icelake-client, icelake-server, tigerlake, knl, knm, lakemont, k6, k6-2, k6-3,
+// TUNE_X86-SAME: athlon, athlon-tbird, athlon-xp, athlon-mp, athlon-4, k8, athlon64,
+// TUNE_X86-SAME: athlon-fx, opteron, k8-sse3, athlon64-sse3, opteron-sse3, amdfam10,
+// TUNE_X86-SAME: barcelona, btver1, btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2,
+// TUNE_X86-SAME: x86-64, geode
+
+// RUN: not %clang_cc1 -triple x86_64--- -tune-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix TUNE_X86_64
+// TUNE_X86_64: error: unknown target CPU 'not-a-cpu'
+// TUNE_X86_64: note: valid target CPU values are: nocona, core2, penryn, bonnell,
+// TUNE_X86_64-SAME: atom, silvermont, slm, goldmont, goldmont-plus, tremont, nehalem, corei7, westmere,
+// TUNE_X86_64-SAME: sandybridge, corei7-avx, ivybridge, core-avx-i, haswell,
+// TUNE_X86_64-SAME: core-avx2, broadwell, skylake, skylake-avx512, skx, cascadelake, cooperlake, cannonlake,
+// TUNE_X86_64-SAME: icelake-client, icelake-server, tigerlake, knl, knm, k8, athlon64, athlon-fx, opteron, k8-sse3,
+// TUNE_X86_64-SAME: athlon64-sse3, opteron-sse3, amdfam10, barcelona, btver1,
+// TUNE_X86_64-SAME: btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2, x86-64
+
 // RUN: not %clang_cc1 -triple nvptx--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix NVPTX
 // NVPTX: error: unknown target CPU 'not-a-cpu'
 // NVPTX: note: valid target CPU values are: sm_20, sm_21, sm_30, sm_32, sm_35,
 // NVPTX-SAME: sm_37, sm_50, sm_52, sm_53, sm_60, sm_61, sm_62, sm_70, sm_72
 
 // RUN: not %clang_cc1 -triple r600--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix R600
 // R600: error: unknown target CPU 'not-a-cpu'
 // R600: note: valid target CPU values are: r600, rv630, rv635, r630, rs780,