[NVPTX] Assign valid global names

hahnjo · hahnjo · commit 5db24d7c2290 · 2017-12-04T14:19:33.000Z
PTX requires that identifiers consist only of [a-zA-Z0-9_$]. The existing pass already ensured this for globals and this patch adds the cleanup for functions with local linkage. However, there was a different problem in the case of collisions of the adjusted name: The ValueSymbolTable then automatically appended ".N" with increasing Ns to get a unique name while helping the ABI demangling. Special case this behavior to omit the dots and append N directly. This will always give us legal names according to the PTX requirements. Differential Revision: https://reviews.llvm.org/D40573 llvm-svn: 319657
diff --git a/llvm/lib/IR/ValueSymbolTable.cpp b/llvm/lib/IR/ValueSymbolTable.cpp
@@ -13,7 +13,9 @@
 
 #include "llvm/IR/ValueSymbolTable.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
 #include "llvm/Support/Casting.h"
@@ -45,8 +47,17 @@ ValueName *ValueSymbolTable::makeUniqueName(Value *V,
     // Trim any suffix off and append the next number.
     UniqueName.resize(BaseSize);
     raw_svector_ostream S(UniqueName);
-    if (isa<GlobalValue>(V))
-      S << ".";
+    if (auto *GV = dyn_cast<GlobalValue>(V)) {
+      // A dot is appended to mark it as clone during ABI demangling so that
+      // for example "_Z1fv" and "_Z1fv.1" both demangle to "f()", the second
+      // one being a clone.
+      // On NVPTX we cannot use a dot because PTX only allows [A-Za-z0-9_$] for
+      // identifiers. This breaks ABI demangling but at least ptxas accepts and
+      // compiles the program.
+      const Module *M = GV->getParent();
+      if (!(M && Triple(M->getTargetTriple()).isNVPTX()))
+        S << ".";
+    }
     S << ++LastUnique;
 
     // Try insert the vmap entry with this suffix.
diff --git a/llvm/lib/Target/NVPTX/NVPTXAssignValidGlobalNames.cpp b/llvm/lib/Target/NVPTX/NVPTXAssignValidGlobalNames.cpp
@@ -18,6 +18,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "NVPTX.h"
+#include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
@@ -61,6 +62,11 @@ bool NVPTXAssignValidGlobalNames::runOnModule(Module &M) {
     }
   }
 
+  // Do the same for local functions.
+  for (Function &F : M.functions())
+    if (F.hasLocalLinkage())
+      F.setName(cleanUpName(F.getName()));
+
   return true;
 }
 
diff --git a/llvm/test/CodeGen/NVPTX/symbol-naming.ll b/llvm/test/CodeGen/NVPTX/symbol-naming.ll
@@ -1,17 +1,17 @@
-; RUN: llc < %s -march=nvptx -mcpu=sm_20 | FileCheck %s --check-prefix=PTX32
-; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 | FileCheck %s --check-prefix=PTX64
+; RUN: llc < %s -march=nvptx -mcpu=sm_20 | FileCheck %s
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 | FileCheck %s
 
 ; Verify that the NVPTX target removes invalid symbol names prior to emitting
 ; PTX.
 
-; PTX32-NOT: .str
-; PTX64-NOT: .str
+; CHECK-NOT: .str
+; CHECK-NOT: .function.
 
-; PTX32-DAG: _$_str.1
-; PTX32-DAG: _$_str
+; CHECK-DAG: _$_str
+; CHECK-DAG: _$_str1
 
-; PTX64-DAG: _$_str.1
-; PTX64-DAG: _$_str
+; CHECK-DAG: _$_function_$_
+; CHECK-DAG: _$_function_$_2
 
 target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64"
 target triple = "nvptx64-unknown-unknown"
@@ -22,10 +22,25 @@ target triple = "nvptx64-unknown-unknown"
 
 
 ; Function Attrs: nounwind
-define void @foo(i32 %a, float %b, i8 signext %c, i32 %e) {
+define internal void @.function.() {
 entry:
   %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i32 0, i32 0))
   ret void
 }
 
+; Function Attrs: nounwind
+define internal void @_$_function_$_() {
+entry:
+  %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @_$_str, i32 0, i32 0))
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @global_function() {
+entry:
+  call void @.function.()
+  call void @_$_function_$_()
+  ret void
+}
+
 declare i32 @printf(i8*, ...)

Original file line number	Diff line number	Diff line change
`@@ -18,6 +18,7 @@`
`18`	`18`	`//===----------------------------------------------------------------------===//`
`19`	`19`
`20`	`20`	`#include "NVPTX.h"`
	`21`	`+#include "llvm/IR/Function.h"`
`21`	`22`	`#include "llvm/IR/GlobalVariable.h"`
`22`	`23`	`#include "llvm/IR/LegacyPassManager.h"`
`23`	`24`	`#include "llvm/IR/Module.h"`
`@@ -61,6 +62,11 @@ bool NVPTXAssignValidGlobalNames::runOnModule(Module &M) {`
`61`	`62`	`}`
`62`	`63`	`}`
`63`	`64`
	`65`	`+ // Do the same for local functions.`
	`66`	`+ for (Function &F : M.functions())`
	`67`	`+ if (F.hasLocalLinkage())`
	`68`	`+ F.setName(cleanUpName(F.getName()));`
	`69`	`+`
`64`	`70`	`return true;`
`65`	`71`	`}`
`66`	`72`