[PATCH] D38333: [X86] Fix using the SJLJ jump table on x86_64

[Martin Storsjö via Phabricator via llvm-commits]

mstorsjo updated this revision to Diff 116932.
mstorsjo retitled this revision from "[X86] Load the SJLJ jump table address into a register on x86_64" to "[X86] Fix using the SJLJ jump table on x86_64".
mstorsjo edited the summary of this revision.
mstorsjo added a comment.

Handled the case of MachineJumpTableInfo::EK_LabelDifference32 as well, which is what the jump table ends up as on win64/x86.


https://reviews.llvm.org/D38333

Files:
  lib/Target/X86/X86ISelLowering.cpp
  test/CodeGen/X86/sjlj-eh.ll


Index: test/CodeGen/X86/sjlj-eh.ll
===================================================================
--- test/CodeGen/X86/sjlj-eh.ll
+++ test/CodeGen/X86/sjlj-eh.ll
@@ -1,5 +1,6 @@
 ; RUN: llc -mtriple i386-windows-gnu -exception-model sjlj -filetype asm -o - %s | FileCheck %s
 ; RUN: llc -mtriple x86_64-windows-gnu -exception-model sjlj -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-X64
+; RUN: llc -mtriple x86_64-linux -exception-model sjlj -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-X64-LINUX
 
 declare void @_Z20function_that_throwsv()
 declare i32 @__gxx_personality_sj0(...)
@@ -116,4 +117,11 @@
 ; CHECK-X64: ud2
 ; CHECK-X64: [[CONT]]:
 ;     *Handlers[UFC.__callsite]
-; CHECK-X64: jmpq *.LJTI
+; CHECK-X64: leaq .[[TABLE:LJTI[0-9]+_[0-9]+]](%rip), %rcx
+; CHECK-X64: movl (%rcx,%rax,4), %eax
+; CHECK-X64: cltq
+; CHECK-X64: addq %rcx, %rax
+; CHECK-X64: jmpq *%rax
+
+; CHECK-X64-LINUX: leaq .[[TABLE:LJTI[0-9]+_[0-9]+]](%rip), %rcx
+; CHECK-X64-LINUX: jmpq *(%rcx,%rax,8)
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -26546,8 +26546,8 @@
   SetupEntryBlockForSjLj(MI, BB, DispatchBB, FI);
 
   // Create the jump table and associated information
-  MachineJumpTableInfo *JTI =
-      MF->getOrCreateJumpTableInfo(getJumpTableEncoding());
+  unsigned JTE = getJumpTableEncoding();
+  MachineJumpTableInfo *JTI = MF->getOrCreateJumpTableInfo(JTE);
   unsigned MJTI = JTI->createJumpTableIndex(LPadList);
 
   const X86RegisterInfo &RI = TII->getRegisterInfo();
@@ -26578,13 +26578,47 @@
       .addImm(LPadList.size());
   BuildMI(DispatchBB, DL, TII->get(X86::JAE_1)).addMBB(TrapBB);
 
-  BuildMI(DispContBB, DL,
-          TII->get(Subtarget.is64Bit() ? X86::JMP64m : X86::JMP32m))
-      .addReg(0)
-      .addImm(Subtarget.is64Bit() ? 8 : 4)
-      .addReg(IReg)
-      .addJumpTableIndex(MJTI)
-      .addReg(0);
+  if (Subtarget.is64Bit()) {
+    unsigned Base = MRI->createVirtualRegister(&X86::GR64RegClass);
+    unsigned IReg64 = MRI->createVirtualRegister(&X86::GR64RegClass);
+
+    BuildMI(DispContBB, DL, TII->get(X86::LEA64r), Base)
+        .addReg(X86::RIP)
+        .addImm(1)
+        .addReg(0)
+        .addJumpTableIndex(MJTI)
+        .addReg(0);
+    BuildMI(DispContBB, DL, TII->get(TargetOpcode::COPY), IReg64).addReg(IReg);
+
+    if (JTE == MachineJumpTableInfo::EK_BlockAddress) {
+      BuildMI(DispContBB, DL, TII->get(X86::JMP64m))
+          .addReg(Base)
+          .addImm(8)
+          .addReg(IReg64)
+          .addImm(0)
+          .addReg(0);
+    } else {
+      assert(JTE == MachineJumpTableInfo::EK_LabelDifference32);
+      BuildMI(DispContBB, DL, TII->get(X86::MOV32rm), IReg)
+          .addReg(Base)
+          .addImm(4)
+          .addReg(IReg64)
+          .addImm(0)
+          .addReg(0);
+      BuildMI(DispContBB, DL, TII->get(X86::MOVSX64rr32), IReg64).addReg(IReg);
+      BuildMI(DispContBB, DL, TII->get(X86::ADD64rr), IReg64)
+          .addReg(IReg64)
+          .addReg(Base);
+      BuildMI(DispContBB, DL, TII->get(X86::JMP64r)).addReg(IReg64);
+    }
+  } else {
+    BuildMI(DispContBB, DL, TII->get(X86::JMP32m))
+        .addReg(0)
+        .addImm(Subtarget.is64Bit() ? 8 : 4)
+        .addReg(IReg)
+        .addJumpTableIndex(MJTI)
+        .addReg(0);
+  }
 
   // Add the jump table entries as successors to the MBB.
   SmallPtrSet<MachineBasicBlock *, 8> SeenMBBs;


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