[HIP] Support flush denorms bitcode

[ashi1]

Summary

We need to use oclc_daz_opt_on.amdgcn.bc bitcode when option fcuda-flush-denormal-to-zero is enabled for HIP.

[b-sumner]

LGTM

[scchan]

LGTM

[yaxunl]

I think we should have a lit test for linked bitcode files.

lib/Driver/ToolChains/HIP.cpp

78

you can use StringRef here. Please use a more meaningful name, e.g. FlushDenormalControlBC.

[ashi1]

I've changed the string to a more meaningful name, and also added a lit test to check that oclc_daz_opt_on.amdgcn.bc is used.

[ashi1]

This comment was removed by ashi1.

[ashi1]

Fix diff file

[yaxunl]

test/Driver/hip-toolchain-flush-denorms.hip

6 ↗

(On Diff #153127)

we only need test with one arch

7 ↗

(On Diff #153127)

better put the dummy bc files under test/Driver/Inputs/hip_dev_lib

8 ↗

(On Diff #153127)

we also need to test the case without this option

[yaxunl]

lib/Driver/ToolChains/HIP.cpp

85

we need to fix the order. should be ocml, then ockl, then irif. but should do it in another patch

[ashi1]

I've updated. Moved the bitcode files into hip_dev_lib and added test for both on and off flush denorms to zero option.

[yaxunl]

better merge these two tests and rename it as hip-device-libs.hip. We can also add other device lib tests to it later.

[ashi1]

Merged checks for flush denorm on and off into single test hip-device-libs.hip

[yaxunl]

LGTM. Thanks!

lib/Driver/ToolChains/HIP.cpp

     std::string ISAVerBC =
         "oclc_isa_version_" + SubArchName.drop_front(3).str() + ".amdgcn.bc";
 
+    std::string OCLC_daz_opt;
+    if (Args.hasArg(options::OPT_fcuda_flush_denormals_to_zero))
+      OCLC_daz_opt = "oclc_daz_opt_on.amdgcn.bc";
+    else
+      OCLC_daz_opt = "oclc_daz_opt_off.amdgcn.bc";
+
     BCLibs.append({"opencl.amdgcn.bc",
                    "ockl.amdgcn.bc", "irif.amdgcn.bc", "ocml.amdgcn.bc",
                    "oclc_finite_only_off.amdgcn.bc",
-                   "oclc_daz_opt_off.amdgcn.bc",
+                   OCLC_daz_opt,
                    "oclc_correctly_rounded_sqrt_on.amdgcn.bc",
                    "oclc_unsafe_math_off.amdgcn.bc", ISAVerBC});
   }