[llvm] 42c4027 - [AMDGPU][SplitModule] Keep looking for more dependencies after finding an indirect call (#93480)

[via llvm-commits]

Author: Pierre van Houtryve
Date: 2024-05-28T08:18:53+02:00
New Revision: 42c4027729ac7dbfb732a361ab8085d4af0a7a0a

URL: https://github.com/llvm/llvm-project/commit/42c4027729ac7dbfb732a361ab8085d4af0a7a0a
DIFF: https://github.com/llvm/llvm-project/commit/42c4027729ac7dbfb732a361ab8085d4af0a7a0a.diff

LOG: [AMDGPU][SplitModule] Keep looking for more dependencies after finding an indirect call (#93480)

This is just something I noticed while going over this pass logic one
more time and didn't cause issues (yet). If we find an indirect call, we
stop looking assuming we added all functions to the list, but if not all
functions in the module were indirectly callable, some may still be
missing.

Just to be safe, keep looking until we did everything we could to find
dependencies, so we don't accidentally miss one.

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPUSplitModule.cpp
    llvm/test/tools/llvm-split/AMDGPU/kernels-dependency-indirect.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/AMDGPUSplitModule.cpp b/llvm/lib/Target/AMDGPU/AMDGPUSplitModule.cpp
index dab773f28752d..2449fa581842a 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUSplitModule.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUSplitModule.cpp
@@ -340,7 +340,7 @@ static void addAllDependencies(SplitModuleLogger &SML, const CallGraph &CG,
         // TODO: Print an ORE as well ?
         addAllIndirectCallDependencies(M, Fns);
         HadIndirectCall = true;
-        return;
+        continue;
       }
 
       if (Callee->isDeclaration())

diff  --git a/llvm/test/tools/llvm-split/AMDGPU/kernels-dependency-indirect.ll b/llvm/test/tools/llvm-split/AMDGPU/kernels-dependency-indirect.ll
index 9701ac35ce54e..2d870039112cb 100644
--- a/llvm/test/tools/llvm-split/AMDGPU/kernels-dependency-indirect.ll
+++ b/llvm/test/tools/llvm-split/AMDGPU/kernels-dependency-indirect.ll
@@ -10,13 +10,17 @@
 ; We default to putting A/B in P0, alongside a copy
 ; of all helpers who have their address taken.
 ; The other kernels can still go into separate partitions.
+;
+; Note that dependency discovery shouldn't stop upon finding an
+; indirect call. HelperC/D should also end up in P0 as they
+; are dependencies of HelperB.
 
 ; CHECK0-NOT: define
 ; CHECK0: define hidden void @HelperA
 ; CHECK0: define hidden void @HelperB
 ; CHECK0: define hidden void @CallCandidate
-; CHECK0-NOT: define {{.*}} @HelperC
-; CHECK0-NOT: define {{.*}} @HelperD
+; CHECK0: define internal void @HelperC
+; CHECK0: define internal void @HelperD
 ; CHECK0: define amdgpu_kernel void @A
 ; CHECK0: define amdgpu_kernel void @B
 ; CHECK0-NOT: define
@@ -39,7 +43,9 @@ define internal void @HelperA(ptr %call) {
 }
 
 define internal void @HelperB(ptr %call) {
+  call void @HelperC()
   call void %call()
+  call void @HelperD()
   ret void
 }