[X86] Add a memory clobber to the bittest intrinsic inline asm. Get default clobbers from the target

[craig.topper]

Summary

I believe the inline asm emitted here should have a memory clobber since it writes to memory.

It was also missing the dirflag clobber that we use by default along with flags and fpsr. To avoid missing defaults in the future, get the default list from the target

[RKSimon]

clang/test/CodeGen/bittest-intrin.c

45–50

Can you replace the regex with explicit checks for the clobbers here as well?

[craig.topper]

Update more check lines to fully check the clobbers

[rnk]

lgtm

[RKSimon]

LGTM as well cheers

clang/lib/CodeGen/CGBuiltin.cpp

static llvm::Value *EmitX86BitTestIntrinsic(CodeGenFunction &CGF,
   if (BT.Interlocking != BitTest::Unlocked)
     AsmOS << "lock ";
   AsmOS << "bt";
   if (Action)
     AsmOS << Action;
   AsmOS << SizeSuffix << " $2, ($1)\n\tsetc ${0:b}";
 
   // Build the constraints. FIXME: We should support immediates when possible.
-  std::string Constraints = "=r,r,r,~{cc},~{flags},~{fpsr}";
+  std::string Constraints = "=r,r,r,~{cc},~{memory}";
+  std::string MachineClobbers = CGF.getTarget().getClobbers();
+  if (!MachineClobbers.empty()) {
+    Constraints += ',';
+    Constraints += MachineClobbers;
+  }
   llvm::IntegerType *IntType = llvm::IntegerType::get(
       CGF.getLLVMContext(),
       CGF.getContext().getTypeSize(E->getArg(1)->getType()));
   llvm::Type *IntPtrType = IntType->getPointerTo();
   llvm::FunctionType *FTy =
       llvm::FunctionType::get(CGF.Int8Ty, {IntPtrType, IntType}, false);
 
   llvm::InlineAsm *IA =

clang/test/CodeGen/bittest-intrin.c

void test_arm(long *base, long idx) {
   sink = _interlockedbittestandreset_nf(base, idx);
   sink = _interlockedbittestandset_acq(base, idx);
   sink = _interlockedbittestandset_rel(base, idx);
   sink = _interlockedbittestandset_nf(base, idx);
 }
 #endif
 
 // X64-LABEL: define dso_local void @test32(i32* %base, i32 %idx)
-// X64: call i8 asm sideeffect "btl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
-// X64: call i8 asm sideeffect "btcl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
-// X64: call i8 asm sideeffect "btrl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
-// X64: call i8 asm sideeffect "btsl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
-// X64: call i8 asm sideeffect "lock btrl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
-// X64: call i8 asm sideeffect "lock btsl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i32* %{{.*}}, i32 {{.*}})
+// X64: call i8 asm sideeffect "btl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32 {{.*}})
+// X64: call i8 asm sideeffect "btcl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32 {{.*}})
+// X64: call i8 asm sideeffect "btrl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32 {{.*}})
+// X64: call i8 asm sideeffect "btsl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32 {{.*}})
+// X64: call i8 asm sideeffect "lock btrl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32 {{.*}})
+// X64: call i8 asm sideeffect "lock btsl $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32 {{.*}})
 
 // X64-LABEL: define dso_local void @test64(i64* %base, i64 %idx)
-// X64: call i8 asm sideeffect "btq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
-// X64: call i8 asm sideeffect "btcq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
-// X64: call i8 asm sideeffect "btrq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
-// X64: call i8 asm sideeffect "btsq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
-// X64: call i8 asm sideeffect "lock btrq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
-// X64: call i8 asm sideeffect "lock btsq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{{.*}}"(i64* %{{.*}}, i64 {{.*}})
+// X64: call i8 asm sideeffect "btq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i64* %{{.*}}, i64 {{.*}})
+// X64: call i8 asm sideeffect "btcq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i64* %{{.*}}, i64 {{.*}})
+// X64: call i8 asm sideeffect "btrq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i64* %{{.*}}, i64 {{.*}})
+// X64: call i8 asm sideeffect "btsq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i64* %{{.*}}, i64 {{.*}})
+// X64: call i8 asm sideeffect "lock btrq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i64* %{{.*}}, i64 {{.*}})
+// X64: call i8 asm sideeffect "lock btsq $2, ($1)\0A\09setc ${0:b}", "=r,r,r,~{cc},~{memory},~{dirflag},~{fpsr},~{flags}"(i64* %{{.*}}, i64 {{.*}})
 
 // ARM-LABEL: define dso_local {{.*}}void @test32(i32* %base, i32 %idx)
 // ARM: %[[IDXHI:[^ ]*]] = ashr i32 %{{.*}}, 3
 // ARM: %[[BASE:[^ ]*]] = bitcast i32* %{{.*}} to i8*
 // ARM: %[[BYTEADDR:[^ ]*]] = getelementptr inbounds i8, i8* %[[BASE]], i32 %[[IDXHI]]
 // ARM: %[[IDX8:[^ ]*]] = trunc i32 %{{.*}} to i8
 // ARM: %[[IDXLO:[^ ]*]] = and i8 %[[IDX8]], 7
 // ARM: %[[BYTE:[^ ]*]] = load i8, i8* %[[BYTEADDR]], align 1