AArch64: fix conversion of 'J' inline asm constraints.

'J' represents a negative number suitable for an add/sub alias
instruction, but while preparing it to become an int64_t we were
mangling the sign extension. So "i32 -1" became 0xffffffffLL, for
example.

Should fix one half of PR20456.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214052 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AArch64/AArch64ISelLowering.cpp b/lib/Target/AArch64/AArch64ISelLowering.cpp
index 7776206aafae9c7635c46207dba315b54ca67573..994013f79bee38fedcb430bc8ae2bc01b281a029 100644 (file)
--- a/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -4013,8 +4013,10 @@ void AArch64TargetLowering::LowerAsmOperandForConstraint(
       return;
     case 'J': {
       uint64_t NVal = -C->getSExtValue();
-      if (isUInt<12>(NVal) || isShiftedUInt<12, 12>(NVal))
+      if (isUInt<12>(NVal) || isShiftedUInt<12, 12>(NVal)) {
+        CVal = C->getSExtValue();
         break;
+      }
       return;
     }
     // The K and L constraints apply *only* to logical immediates, including

diff --git a/test/CodeGen/AArch64/arm64-inline-asm.ll b/test/CodeGen/AArch64/arm64-inline-asm.ll
index d76cca3f21c6464b411a1b8f1b09f6129175d4dd..9c8bcaadc17c394ea63cdb30e5265f143857d5c5 100644 (file)
--- a/test/CodeGen/AArch64/arm64-inline-asm.ll
+++ b/test/CodeGen/AArch64/arm64-inline-asm.ll
@@ -87,13 +87,17 @@ entry:
   ret i32 %1
 }
 
-define i32 @constraint_J(i32 %i, i32 %j) nounwind {
+define i32 @constraint_J(i32 %i, i32 %j, i64 %k) nounwind {
 entry:
   ; CHECK-LABEL: constraint_J:
   %0 = tail call i32 asm sideeffect "sub ${0:w}, ${1:w}, $2", "=r,r,J"(i32 %i, i32 -16773120) nounwind
-  ; CHECK: sub   {{w[0-9]+}}, {{w[0-9]+}}, #4278194176
+  ; CHECK: sub   {{w[0-9]+}}, {{w[0-9]+}}, #-16773120
   %1 = tail call i32 asm sideeffect "sub ${0:w}, ${1:w}, $2", "=r,r,J"(i32 %i, i32 -1) nounwind
-  ; CHECK: sub   {{w[0-9]+}}, {{w[0-9]+}}, #4294967295
+  ; CHECK: sub   {{w[0-9]+}}, {{w[0-9]+}}, #-1
+  %2 = tail call i64 asm sideeffect "sub ${0:x}, ${1:x}, $2", "=r,r,J"(i64 %k, i32 -1) nounwind
+  ; CHECK: sub   {{x[0-9]+}}, {{x[0-9]+}}, #-1
+  %3 = tail call i64 asm sideeffect "sub ${0:x}, ${1:x}, $2", "=r,r,J"(i64 %k, i64 -1) nounwind
+  ; CHECK: sub   {{x[0-9]+}}, {{x[0-9]+}}, #-1
   ret i32 %1
 }