[llvm] r224165 - [ARMConstantIsland] Insert tbb/tbh optimization where previous jump table resided.

[Chad Rosier]

Author: mcrosier
Date: Fri Dec 12 17:27:40 2014
New Revision: 224165

URL: http://llvm.org/viewvc/llvm-project?rev=224165&view=rev
Log:
[ARMConstantIsland] Insert tbb/tbh optimization where previous jump table resided.

Added:
    llvm/trunk/test/CodeGen/Thumb2/constant-islands-jump-table.ll
Modified:
    llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp?rev=224165&r1=224164&r2=224165&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp Fri Dec 12 17:27:40 2014
@@ -1952,7 +1952,9 @@ bool ARMConstantIslands::optimizeThumb2J
       DEBUG(dbgs() << "Shrink JT: " << *MI << "     addr: " << *AddrMI
                    << "      lea: " << *LeaMI);
       unsigned Opc = ByteOk ? ARM::t2TBB_JT : ARM::t2TBH_JT;
-      MachineInstr *NewJTMI = BuildMI(MBB, MI->getDebugLoc(), TII->get(Opc))
+      MachineBasicBlock::iterator MI_JT = MI;
+      MachineInstr *NewJTMI =
+        BuildMI(*MBB, MI_JT, MI->getDebugLoc(), TII->get(Opc))
         .addReg(IdxReg, getKillRegState(IdxRegKill))
         .addJumpTableIndex(JTI, JTOP.getTargetFlags())
         .addImm(MI->getOperand(JTOpIdx+1).getImm());

Added: llvm/trunk/test/CodeGen/Thumb2/constant-islands-jump-table.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb2/constant-islands-jump-table.ll?rev=224165&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb2/constant-islands-jump-table.ll (added)
+++ llvm/trunk/test/CodeGen/Thumb2/constant-islands-jump-table.ll Fri Dec 12 17:27:40 2014
@@ -0,0 +1,47 @@
+; RUN: llc < %s -mtriple=thumbv7-linux-gnueabihf -O1 %s -o - | FileCheck %s
+
+; CHECK-LABEL: test_jump_table:
+; CHECK: b .LBB
+; CHECK-NOT: tbh
+
+define i32 @test_jump_table(i32 %x, float %in) {
+
+h1:
+
+ %b0 = fadd float %in, 1234.5
+ %b1 = fptoui float %b0 to i32
+  
+  switch i32 %x, label %h2 [
+    i32 0, label %h3
+    i32 2, label %h4
+    i32 4, label %h5
+    i32 6, label %h6
+  ]
+
+h2:
+  %a0 = add i32 %x, 5
+  br label %h3
+
+h3:
+  %d2 = phi i32 [%b1, %h1], [%a0, %h2]
+  %d3 = add i32 %d2, 3
+  br label %h4
+
+h4:
+  %c2 = phi i32 [%b1, %h1], [%d3, %h3]
+  %c3 = add i32 %c2, 5
+  br label %h5
+
+h5:
+  %a2 = phi i32 [%b1, %h1], [%c3, %h4]
+  %a3 = add i32 %a2, 6
+  br label %h6
+
+h6:
+  %y = phi i32 [0, %h1], [%a3, %h5]
+  call i32 @llvm.arm.space(i32 2000, i32 undef)
+  ret i32 %y
+  
+}
+
+declare i32 @llvm.arm.space(i32, i32)