[PATCH] D46314: [X86][AMD][Bulldozer] Unbreak Bulldozer sub-type detection.
Roman Lebedev via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue May 1 07:30:54 PDT 2018
lebedev.ri created this revision.
lebedev.ri added reviewers: craig.topper, GBuella, RKSimon, asbirlea, echristo, bkramer, spatel.
Herald added subscribers: JDevlieghere, arichardson, aprantl, sdardis.
I have discovered an issue by accident.
$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 8
On-line CPU(s) list: 0-7
Thread(s) per core: 2
Core(s) per socket: 4
Socket(s): 1
NUMA node(s): 1
Vendor ID: AuthenticAMD
CPU family: 21
Model: 2
Model name: AMD FX(tm)-8350 Eight-Core Processor
Stepping: 0
CPU MHz: 3584.018
CPU max MHz: 4000.0000
CPU min MHz: 1400.0000
BogoMIPS: 8027.22
Virtualization: AMD-V
L1d cache: 16K
L1i cache: 64K
L2 cache: 2048K
L3 cache: 8192K
NUMA node0 CPU(s): 0-7
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core perfctr_nb cpb hw_pstate vmmcall bmi1 arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold
So this is model-2 bulldozer AMD CPU.
GCC agrees:
$ echo | gcc -E - -march=native -###
<...>
/usr/lib/gcc/x86_64-linux-gnu/7/cc1 -E -quiet -imultiarch x86_64-linux-gnu - "-march=bdver2" -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -msse4a -mcx16 -msahf -mno-movbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mlwp -mfma -mfma4 -mxop -mbmi -mno-sgx -mno-bmi2 -mtbm -mavx -mno-avx2 -msse4.2 -msse4.1 -mlzcnt -mno-rtm -mno-hle -mno-rdrnd -mf16c -mno-fsgsbase -mno-rdseed -mprfchw -mno-adx -mfxsr -mxsave -mno-xsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves -mno-avx512dq -mno-avx512bw -mno-avx512vl -mno-avx512ifma -mno-avx512vbmi -mno-avx5124fmaps -mno-avx5124vnniw -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mno-rdpid --param "l1-cache-size=16" --param "l1-cache-line-size=64" --param "l2-cache-size=2048" "-mtune=bdver2"
<...>
But clang does not: (look for `bdver1`)
$ echo | clang -E - -march=native -###
clang version 7.0.0- (trunk)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
"/usr/lib/llvm-7/bin/clang" "-cc1" "-triple" "x86_64-pc-linux-gnu" "-E" "-disable-free" "-disable-llvm-verifier" "-discard-value-names" "-main-file-name" "-" "-mrelocation-model" "static" "-mthread-model" "posix" "-mdisable-fp-elim" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-munwind-tables" "-fuse-init-array" "-target-cpu" "bdver1" "-target-feature" "+sse2" "-target-feature" "+cx16" "-target-feature" "+sahf" "-target-feature" "+tbm" "-target-feature" "-avx512ifma" "-target-feature" "-sha" "-target-feature" "-gfni" "-target-feature" "+fma4" "-target-feature" "-vpclmulqdq" "-target-feature" "+prfchw" "-target-feature" "-bmi2" "-target-feature" "-cldemote" "-target-feature" "-fsgsbase" "-target-feature" "-xsavec" "-target-feature" "+popcnt" "-target-feature" "+aes" "-target-feature" "-avx512bitalg" "-target-feature" "-xsaves" "-target-feature" "-avx512er" "-target-feature" "-avx512vnni" "-target-feature" "-avx512vpopcntdq" "-target-feature" "-clwb" "-target-feature" "-avx512f" "-target-feature" "-clzero" "-target-feature" "-pku" "-target-feature" "+mmx" "-target-feature" "+lwp" "-target-feature" "-rdpid" "-target-feature" "+xop" "-target-feature" "-rdseed" "-target-feature" "-waitpkg" "-target-feature" "-ibt" "-target-feature" "+sse4a" "-target-feature" "-avx512bw" "-target-feature" "-clflushopt" "-target-feature" "+xsave" "-target-feature" "-avx512vbmi2" "-target-feature" "-avx512vl" "-target-feature" "-avx512cd" "-target-feature" "+avx" "-target-feature" "-vaes" "-target-feature" "-rtm" "-target-feature" "+fma" "-target-feature" "+bmi" "-target-feature" "-rdrnd" "-target-feature" "-mwaitx" "-target-feature" "+sse4.1" "-target-feature" "+sse4.2" "-target-feature" "-avx2" "-target-feature" "-wbnoinvd" "-target-feature" "+sse" "-target-feature" "+lzcnt" "-target-feature" "+pclmul" "-target-feature" "-prefetchwt1" "-target-feature" "+f16c" "-target-feature" "+ssse3" "-target-feature" "-sgx" "-target-feature" "-shstk" "-target-feature" "+cmov" "-target-feature" "-avx512vbmi" "-target-feature" "-movbe" "-target-feature" "-xsaveopt" "-target-feature" "-avx512dq" "-target-feature" "-adx" "-target-feature" "-avx512pf" "-target-feature" "+sse3" "-dwarf-column-info" "-debugger-tuning=gdb" "-resource-dir" "/usr/lib/llvm-7/lib/clang/7.0.0" "-internal-isystem" "/usr/local/include" "-internal-isystem" "/usr/lib/llvm-7/lib/clang/7.0.0/include" "-internal-externc-isystem" "/usr/include/x86_64-linux-gnu" "-internal-externc-isystem" "/include" "-internal-externc-isystem" "/usr/include" "-fdebug-compilation-dir" "/build/llvm-build-Clang-release" "-ferror-limit" "19" "-fmessage-length" "271" "-fobjc-runtime=gcc" "-fdiagnostics-show-option" "-fcolor-diagnostics" "-o" "-" "-x" "c" "-"
So clang, unlike gcc, considers this to be `bdver1`.
After some digging, i've come across `getAMDProcessorTypeAndSubtype()` in `Host.cpp`.
I have added the following debug printf after the call to that function in `sys::getHostCPUName()`:
errs() << "Family " << Family << " Model " << Model << " Type " << Type "\n";
Which produced:
Family 21 Model 2 Type 5
Which matches the `lscpu` output.
So the model is indeed 2, but the check for `X86::AMDFAM15H_BDVER2` is `Model >= 0x10 && Model <= 0x1f`.
I can only assume that these checks were either blindly copied from somewhere else,
without actually checking that they do what they are supposed to do, or that they were indeed correct,
but some other cpuid reading changes broke them along the way.
It does not help that the code can't be tested at the moment.
With this logical change, the `bdver2` is properly detected.
$ echo | /build/llvm-build-Clang-release/bin/clang -E - -march=native -###
clang version 7.0.0 (trunk 331249) (llvm/trunk 331256)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /build/llvm-build-Clang-release/bin
"/build/llvm-build-Clang-release/bin/clang-7" "-cc1" "-triple" "x86_64-unknown-linux-gnu" "-E" "-disable-free" "-main-file-name" "-" "-mrelocation-model" "static" "-mthread-model" "posix" "-mdisable-fp-elim" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-munwind-tables" "-fuse-init-array" "-target-cpu" "bdver2" "-target-feature" "+sse2" "-target-feature" "+cx16" "-target-feature" "+sahf" "-target-feature" "+tbm" "-target-feature" "-avx512ifma" "-target-feature" "-sha" "-target-feature" "-gfni" "-target-feature" "+fma4" "-target-feature" "-vpclmulqdq" "-target-feature" "+prfchw" "-target-feature" "-bmi2" "-target-feature" "-cldemote" "-target-feature" "-fsgsbase" "-target-feature" "-xsavec" "-target-feature" "+popcnt" "-target-feature" "+aes" "-target-feature" "-avx512bitalg" "-target-feature" "-movdiri" "-target-feature" "-xsaves" "-target-feature" "-avx512er" "-target-feature" "-avx512vnni" "-target-feature" "-avx512vpopcntdq" "-target-feature" "-clwb" "-target-feature" "-avx512f" "-target-feature" "-clzero" "-target-feature" "-pku" "-target-feature" "+mmx" "-target-feature" "+lwp" "-target-feature" "-rdpid" "-target-feature" "+xop" "-target-feature" "-rdseed" "-target-feature" "-waitpkg" "-target-feature" "-movdir64b" "-target-feature" "-ibt" "-target-feature" "+sse4a" "-target-feature" "-avx512bw" "-target-feature" "-clflushopt" "-target-feature" "+xsave" "-target-feature" "-avx512vbmi2" "-target-feature" "-avx512vl" "-target-feature" "-avx512cd" "-target-feature" "+avx" "-target-feature" "-vaes" "-target-feature" "-rtm" "-target-feature" "+fma" "-target-feature" "+bmi" "-target-feature" "-rdrnd" "-target-feature" "-mwaitx" "-target-feature" "+sse4.1" "-target-feature" "+sse4.2" "-target-feature" "-avx2" "-target-feature" "-wbnoinvd" "-target-feature" "+sse" "-target-feature" "+lzcnt" "-target-feature" "+pclmul" "-target-feature" "-prefetchwt1" "-target-feature" "+f16c" "-target-feature" "+ssse3" "-target-feature" "-sgx" "-target-feature" "-shstk" "-target-feature" "+cmov" "-target-feature" "-avx512vbmi" "-target-feature" "-movbe" "-target-feature" "-xsaveopt" "-target-feature" "-avx512dq" "-target-feature" "-adx" "-target-feature" "-avx512pf" "-target-feature" "+sse3" "-dwarf-column-info" "-debugger-tuning=gdb" "-resource-dir" "/build/llvm-build-Clang-release/lib/clang/7.0.0" "-internal-isystem" "/usr/local/include" "-internal-isystem" "/build/llvm-build-Clang-release/lib/clang/7.0.0/include" "-internal-externc-isystem" "/usr/include/x86_64-linux-gnu" "-internal-externc-isystem" "/include" "-internal-externc-isystem" "/usr/include" "-fdebug-compilation-dir" "/build/llvm-build-Clang-release" "-ferror-limit" "19" "-fmessage-length" "271" "-fobjc-runtime=gcc" "-fdiagnostics-show-option" "-fcolor-diagnostics" "-o" "-" "-x" "c" "-"
**I don't have access to other models, so i can't know that this is the full solution.**
Thoughts?
Repository:
rL LLVM
https://reviews.llvm.org/D46314
Files:
lib/Support/Host.cpp
Index: lib/Support/Host.cpp
===================================================================
--- lib/Support/Host.cpp
+++ lib/Support/Host.cpp
@@ -832,19 +832,17 @@
break; // "btver1";
case 21:
*Type = X86::AMDFAM15H;
- if (Model >= 0x60 && Model <= 0x7f) {
+ switch (Model) {
+ case 4:
*Subtype = X86::AMDFAM15H_BDVER4;
break; // "bdver4"; 60h-7Fh: Excavator
- }
- if (Model >= 0x30 && Model <= 0x3f) {
+ case 3:
*Subtype = X86::AMDFAM15H_BDVER3;
break; // "bdver3"; 30h-3Fh: Steamroller
- }
- if (Model >= 0x10 && Model <= 0x1f) {
+ case 2:
*Subtype = X86::AMDFAM15H_BDVER2;
break; // "bdver2"; 10h-1Fh: Piledriver
- }
- if (Model <= 0x0f) {
+ case 1:
*Subtype = X86::AMDFAM15H_BDVER1;
break; // "bdver1"; 00h-0Fh: Bulldozer
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D46314.144709.patch
Type: text/x-patch
Size: 842 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180501/83230c76/attachment.bin>
More information about the llvm-commits
mailing list