Remove special cases for invoke of non-throwing inline-asm.

Non-throwing inline asm infers the nounwind attribute in
instcombine. Thus, it can be handled in the same manner as
non-throwing target functions are generally. Further special casing is
unnecessary complexity.

Author: jyknight

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -2591,9 +2591,6 @@ bool IRTranslator::translateInvoke(const User &U,
 
   bool LowerInlineAsm = I.isInlineAsm();
   bool NeedEHLabel = true;
-  // If it can't throw then use a fast-path without emitting EH labels.
-  if (LowerInlineAsm)
-    NeedEHLabel = (cast<InlineAsm>(I.getCalledOperand()))->canThrow();
 
   // Emit the actual call, bracketed by EH_LABELs so that the MF knows about
   // the region covered by the try.

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -8896,7 +8896,7 @@ void SelectionDAGBuilder::visitInlineAsm(const CallBase &Call,
   // memory and is nonvolatile.
   SDValue Flag, Chain = (HasSideEffect) ? getRoot() : DAG.getRoot();
 
-  bool EmitEHLabels = isa<InvokeInst>(Call) && IA->canThrow();
+  bool EmitEHLabels = isa<InvokeInst>(Call);
   if (EmitEHLabels) {
     assert(EHPadBB && "InvokeInst must have an EHPadBB");
   }

llvm/lib/Transforms/Utils/InlineFunction.cpp

@@ -550,13 +550,6 @@ static BasicBlock *HandleCallsInBlockInlinedThroughInvoke(
     if (!CI || CI->doesNotThrow())
       continue;
 
-    if (CI->isInlineAsm()) {
-      InlineAsm *IA = cast<InlineAsm>(CI->getCalledOperand());
-      if (!IA->canThrow()) {
-        continue;
-      }
-    }
-
     // We do not need to (and in fact, cannot) convert possibly throwing calls
     // to @llvm.experimental_deoptimize (resp. @llvm.experimental.guard) into
     // invokes.  The caller's "segment" of the deoptimization continuation

llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-no-unwind-inline-asm.ll

@@ -16,9 +16,9 @@ entry:
 ; CHECK-LABEL: name: test
 ; CHECK: body:
 ; CHECK-NEXT: bb.1.entry
-; CHECK-NOT: EH_LABEL
+; CHECK: EH_LABEL
 ; CHECK: INLINEASM
-; CHECK-NOT: EH_LABEL
+; CHECK: EH_LABEL
 
   invoke void asm sideeffect "bl trap", ""()
           to label %invoke.cont unwind label %lpad

llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-unwind-inline-asm.ll

@@ -68,8 +68,11 @@ define void @test2() #0 personality ptr @__gcc_personality_v0 {
   ; CHECK-NEXT:   successors: %bb.2(0x40000000), %bb.3(0x40000000)
   ; CHECK-NEXT: {{  $}}
   ; CHECK-NEXT:   [[DEF:%[0-9]+]]:_(p0) = G_IMPLICIT_DEF
+  ; CHECK-NEXT:   G_INVOKE_REGION_START
+  ; CHECK-NEXT:   EH_LABEL <mcsymbol >
   ; CHECK-NEXT:   [[COPY:%[0-9]+]]:gpr64common = COPY [[DEF]](p0)
   ; CHECK-NEXT:   INLINEASM &"", 1 /* sideeffect attdialect */, 2555913 /* reguse:GPR64common */, [[COPY]]
+  ; CHECK-NEXT:   EH_LABEL <mcsymbol >
   ; CHECK-NEXT:   G_BR %bb.2
   ; CHECK-NEXT: {{  $}}
   ; CHECK-NEXT: bb.2.a:

llvm/test/CodeGen/X86/no-seh-unwind-inline-asm-codegen.ll

@@ -26,7 +26,7 @@ define void @caller() personality ptr @__objc_personality_v0 {
 }
 
 define void @callee_with_asm() {
-  call void asm sideeffect "mov\09r7, r7\09\09@ marker for objc_retainAutoreleaseReturnValue", ""()
+  call void asm sideeffect "mov\09r7, r7\09\09@ marker for objc_retainAutoreleaseReturnValue", ""() nounwind
   ret void
 }
 

llvm/test/CodeGen/X86/no-unwind-inline-asm-codegen.ll

@@ -12,8 +12,8 @@ entry:
 
 define dso_local void @proxy() personality ptr @__gxx_personality_v0 {
 entry:
-  call void asm sideeffect "call trap", "~{dirflag},~{fpsr},~{flags}"()
-  call void asm sideeffect "call trap", "~{dirflag},~{fpsr},~{flags}"()
+  call void asm sideeffect "call trap", "~{dirflag},~{fpsr},~{flags}"() nounwind
+  call void asm sideeffect "call trap", "~{dirflag},~{fpsr},~{flags}"() nounwind
   ret void
 }