Generate LEA for label expressions

1 files changed, 16 insertions, 0 deletions

diff --git a/compiler/GHC/CmmToAsm/X86/CodeGen.hs b/compiler/GHC/CmmToAsm/X86/CodeGen.hs
index 635070b610..b920c7ec05 100644
--- a/compiler/GHC/CmmToAsm/X86/CodeGen.hs
+++ b/compiler/GHC/CmmToAsm/X86/CodeGen.hs
@@ -1177,6 +1177,22 @@ getRegister' _ is32Bit (CmmLit (CmmInt 0 width))
     in
         return (Any format code)
 
+-- Handle symbol references with LEA and %rip-relative addressing.
+-- See Note [%rip-relative addressing on x86-64].
+getRegister' platform is32Bit (CmmLit lit)
+  | is_label lit
+  , not is32Bit
+  = do let format = cmmTypeFormat (cmmLitType platform lit)
+           imm = litToImm lit
+           op = OpAddr (AddrBaseIndex EABaseRip EAIndexNone imm)
+           code dst = unitOL (LEA format op (OpReg dst))
+       return (Any format code)
+  where
+    is_label (CmmLabel {})        = True
+    is_label (CmmLabelOff {})     = True
+    is_label (CmmLabelDiffOff {}) = True
+    is_label _                    = False
+
   -- optimisation for loading small literals on x86_64: take advantage
   -- of the automatic zero-extension from 32 to 64 bits, because the 32-bit
   -- instruction forms are shorter.