[llvm] bb6c23b - [NFC][X86] Avoid redundant work inspecting callee

[Philip Reames via llvm-commits]

Author: Philip Reames
Date: 2021-02-01T15:24:41-08:00
New Revision: bb6c23b1f50780390eafd73aac1a2a895a8971a4

URL: https://github.com/llvm/llvm-project/commit/bb6c23b1f50780390eafd73aac1a2a895a8971a4
DIFF: https://github.com/llvm/llvm-project/commit/bb6c23b1f50780390eafd73aac1a2a895a8971a4.diff

LOG: [NFC][X86] Avoid redundant work inspecting callee

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86FastISel.cpp
    llvm/lib/Target/X86/X86ISelLowering.cpp
    llvm/test/CodeGen/X86/x86-no_caller_saved_registers-preserve.ll
    llvm/test/CodeGen/X86/x86-no_caller_saved_registers.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp
index caf158102230..6838d39e13e8 100644
--- a/llvm/lib/Target/X86/X86FastISel.cpp
+++ b/llvm/lib/Target/X86/X86FastISel.cpp
@@ -3206,7 +3206,6 @@ bool X86FastISel::fastLowerCall(CallLoweringInfo &CLI) {
   bool IsWin64        = Subtarget->isCallingConvWin64(CC);
 
   const CallInst *CI = dyn_cast_or_null<CallInst>(CLI.CB);
-  const Function *CalledFn = CI ? CI->getCalledFunction() : nullptr;
 
   // Call / invoke instructions with NoCfCheck attribute require special
   // handling.
@@ -3215,8 +3214,7 @@ bool X86FastISel::fastLowerCall(CallLoweringInfo &CLI) {
     return false;
 
   // Functions with no_caller_saved_registers that need special handling.
-  if ((CI && CI->hasFnAttr("no_caller_saved_registers")) ||
-      (CalledFn && CalledFn->hasFnAttribute("no_caller_saved_registers")))
+  if ((CI && CI->hasFnAttr("no_caller_saved_registers")))
     return false;
 
   // Functions using thunks for indirect calls need to use SDISel.

diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 9a1c9bf7aa3b..5befee9f7ce7 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -3910,9 +3910,7 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       CallConv == CallingConv::Tail;
   X86MachineFunctionInfo *X86Info = MF.getInfo<X86MachineFunctionInfo>();
   const auto *CI = dyn_cast_or_null<CallInst>(CLI.CB);
-  const Function *Fn = CI ? CI->getCalledFunction() : nullptr;
-  bool HasNCSR = (CI && CI->hasFnAttr("no_caller_saved_registers")) ||
-                 (Fn && Fn->hasFnAttribute("no_caller_saved_registers"));
+  bool HasNCSR = (CI && CI->hasFnAttr("no_caller_saved_registers"));
   const auto *II = dyn_cast_or_null<InvokeInst>(CLI.CB);
   bool HasNoCfCheck =
       (CI && CI->doesNoCfCheck()) || (II && II->doesNoCfCheck());

diff  --git a/llvm/test/CodeGen/X86/x86-no_caller_saved_registers-preserve.ll b/llvm/test/CodeGen/X86/x86-no_caller_saved_registers-preserve.ll
index 2687e735300b..bfb963bb7540 100644
--- a/llvm/test/CodeGen/X86/x86-no_caller_saved_registers-preserve.ll
+++ b/llvm/test/CodeGen/X86/x86-no_caller_saved_registers-preserve.ll
@@ -41,7 +41,7 @@ define x86_64_sysvcc float @foo(i32 %a0, i32 %a1, float %b0) {
 ; CHECK-NEXT:  cvtsi2ss %eax, %xmm0
 ; CHECK-NEXT:  addss %xmm0, %xmm1
 ; CHECK:       retq
-	%call = call i32 @bar(i32 %a0, i32 %a1, float %b0) #0
+	%call = call i32 @bar(i32 %a0, i32 %a1, float %b0)
 	%c0   = add i32 %a0, %call
 	%c1   = add i32 %c0, %a1
 	%c2 = sitofp i32 %c1 to float

diff  --git a/llvm/test/CodeGen/X86/x86-no_caller_saved_registers.ll b/llvm/test/CodeGen/X86/x86-no_caller_saved_registers.ll
index 7fb82d15b85e..014470f33149 100644
--- a/llvm/test/CodeGen/X86/x86-no_caller_saved_registers.ll
+++ b/llvm/test/CodeGen/X86/x86-no_caller_saved_registers.ll
@@ -28,4 +28,13 @@ entry:
   ret void
 }
 
+; Same as foo, but rely on attribute on @bar decl, not callsite
+define x86_intrcc void @baz(i8* byval(i8) nocapture readnone %c) {
+; CHECK-LABEL: baz
+; CHECK-NOT: xmm
+entry:
+  tail call i32 @bar(i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8)
+  ret void
+}
+
 attributes #0 = { "no_caller_saved_registers" }