[llvm] 8ad88f1 - Do not write a comma when varargs is the only argument

[Adrian Vogelsgesang via llvm-commits]

Author: Joshua Cao
Date: 2022-11-14T02:46:11-08:00
New Revision: 8ad88f129cc489fc3076f399fd9c1bebc6e28bf1

URL: https://github.com/llvm/llvm-project/commit/8ad88f129cc489fc3076f399fd9c1bebc6e28bf1
DIFF: https://github.com/llvm/llvm-project/commit/8ad88f129cc489fc3076f399fd9c1bebc6e28bf1.diff

LOG: Do not write a comma when varargs is the only argument

Fixes https://github.com/llvm/llvm-project/issues/56544

AsmWriter always writes ", ..." when a tail call has a varargs argument. This patch only writes the ", " when there is an argument before the varargs argument.

I did not write a dedicated test this for this change, but I modified an existing test that will test for a regression.

Reviewed By: avogelsgesang

Differential Revision: https://reviews.llvm.org/D137893

Signed-off-by: Adrian Vogelsgesang <avogelsgesang at salesforce.com>

Added: 
    

Modified: 
    llvm/lib/IR/AsmWriter.cpp
    llvm/test/Transforms/Inline/inline-brunch-funnel.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index d49b8710bc9a4..22e12b29843e0 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -4140,7 +4140,6 @@ void AssemblyWriter::printInstruction(const Instruction &I) {
     // If possible, print out the short form of the call instruction.  We can
     // only do this if the first argument is a pointer to a nonvararg function,
     // and if the return type is not a pointer to a function.
-    //
     Out << ' ';
     TypePrinter.print(FTy->isVarArg() ? FTy : RetTy, Out);
     Out << ' ';
@@ -4156,8 +4155,11 @@ void AssemblyWriter::printInstruction(const Instruction &I) {
     // is only to aid readability, musttail calls forward varargs by default.
     if (CI->isMustTailCall() && CI->getParent() &&
         CI->getParent()->getParent() &&
-        CI->getParent()->getParent()->isVarArg())
-      Out << ", ...";
+        CI->getParent()->getParent()->isVarArg()) {
+      if (CI->arg_size() > 0)
+        Out << ", ";
+      Out << "...";
+    }
 
     Out << ')';
     if (PAL.hasFnAttrs())

diff  --git a/llvm/test/Transforms/Inline/inline-brunch-funnel.ll b/llvm/test/Transforms/Inline/inline-brunch-funnel.ll
index 54c6600c038e5..567abc6b94306 100644
--- a/llvm/test/Transforms/Inline/inline-brunch-funnel.ll
+++ b/llvm/test/Transforms/Inline/inline-brunch-funnel.ll
@@ -9,27 +9,27 @@ declare void @llvm.icall.branch.funnel(...)
 ; CHECK-LABEL: define void @fn_musttail(
 define void @fn_musttail() {
   call void (...) @bf_musttail()
-  ; CHECK: call void (...) @bf_musttail(
+  ; CHECK: call void (...) @bf_musttail()
   ret void
 }
 
 ; CHECK-LABEL: define internal void @bf_musttail(
 define internal void @bf_musttail(...) {
   musttail call void (...) @llvm.icall.branch.funnel(...)
-  ; CHECK: musttail call void (...) @llvm.icall.branch.funnel(
+  ; CHECK: musttail call void (...) @llvm.icall.branch.funnel(...)
   ret void
 }
 
 ; CHECK-LABEL: define void @fn_musttail_always(
 define void @fn_musttail_always() {
   call void (...) @bf_musttail_always()
-  ; CHECK: call void (...) @bf_musttail_always(
+  ; CHECK: call void (...) @bf_musttail_always()
   ret void
 }
 
 ; CHECK-LABEL: define internal void @bf_musttail_always(
 define internal void @bf_musttail_always(...) alwaysinline {
   musttail call void (...) @llvm.icall.branch.funnel(...)
-  ; CHECK: musttail call void (...) @llvm.icall.branch.funnel(
+  ; CHECK: musttail call void (...) @llvm.icall.branch.funnel(...)
   ret void
 }