[InitUndef] Also handle inline asm (#108951)

InitUndef should also handle early-clobber / undef conflicts in inline
asm operands. Do this by iterating over all_defs() instead of defs().

The newly added ARM test was generating an "unpredictable STXP instruction,
status is also a source" error prior to this change.

Fixes llvm/llvm-project#106380.

Author: nikic

llvm/lib/CodeGen/InitUndef.cpp

@@ -98,7 +98,7 @@ INITIALIZE_PASS(InitUndef, DEBUG_TYPE, INIT_UNDEF_NAME, false, false)
 char &llvm::InitUndefID = InitUndef::ID;
 
 static bool isEarlyClobberMI(MachineInstr &MI) {
-  return llvm::any_of(MI.defs(), [](const MachineOperand &DefMO) {
+  return llvm::any_of(MI.all_defs(), [](const MachineOperand &DefMO) {
     return DefMO.isReg() && DefMO.isEarlyClobber();
   });
 }

llvm/test/CodeGen/AArch64/arm64-ldxr-stxr.ll

@@ -364,6 +364,19 @@ define dso_local i32 @test_stxp_undef(ptr %p, i64 %x) nounwind {
   ret i32 %res
 }
 
+; Same as previous test, but using inline asm.
+define dso_local i32 @test_stxp_undef_inline_asm(ptr %p, i64 %x) nounwind {
+; CHECK-LABEL: test_stxp_undef_inline_asm:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    //APP
+; CHECK-NEXT:    stxp w8, x9, x1, [x0]
+; CHECK-NEXT:    //NO_APP
+; CHECK-NEXT:    mov w0, w8
+; CHECK-NEXT:    ret
+  %res = call i32 asm sideeffect "stxp ${0:w}, ${2}, ${3}, [${1}]", "=&r,r,r,r,~{memory}"(ptr %p, i64 undef, i64 %x)
+  ret i32 %res
+}
+
 declare i32 @llvm.aarch64.stlxr.p0(i64, ptr) nounwind
 ;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
 ; FALLBACK: {{.*}}

llvm/test/CodeGen/Thumb2/mve-intrinsics/vcaddq.ll

@@ -710,6 +710,19 @@ entry:
   ret <4 x i32> %0
 }
 
+define arm_aapcs_vfpcc <4 x i32> @test_vhcaddq_rot270_s32_undef_inline_asm() {
+; CHECK-LABEL: test_vhcaddq_rot270_s32_undef_inline_asm:
+; CHECK:       @ %bb.0: @ %entry
+; CHECK-NEXT: @APP
+; CHECK-NEXT: vhcadd.s32 q{{[0-9]+}}, q{{[0-9]+}}, q{{[0-9]+}}, #270
+; CHECK-NOT:  vhcadd.s32 q[[REG:[0-9]+]], q{{[0-9]+}}, q[[REG]], #270
+; CHECK-NEXT: @NO_APP
+; CHECK-NEXT:    bx lr
+entry:
+  %0 = call <4 x i32> asm sideeffect "vhcadd.s32 ${0}, ${1}, ${2}, #270", "=&w,w,w,~{memory}"(<4 x i32> undef, <4 x i32> undef)
+  ret <4 x i32> %0
+}
+
 define arm_aapcs_vfpcc <16 x i8> @test_vhcaddq_rot90_x_s8(<16 x i8> %a, <16 x i8> %b, i16 zeroext %p) {
 ; CHECK-LABEL: test_vhcaddq_rot90_x_s8:
 ; CHECK:       @ %bb.0: @ %entry