AMDGPU: Don't add same instruction multiple times to worklist

When the instruction is processed the first time, it may be
deleted resulting in crashes. While the new test adds the same
user to the worklist twice, this particular case doesn't crash
but I'm not sure why.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290191 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AMDGPU/SIInstrInfo.cpp b/lib/Target/AMDGPU/SIInstrInfo.cpp
index 981b63c59a83672ae9e7760e1f1efa3efa2e4769..26a8d22062a90a706542ede53a97c9431fc9666d 100644 (file)
--- a/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -3312,10 +3312,16 @@ void SIInstrInfo::addUsersToMoveToVALUWorklist(
   MachineRegisterInfo &MRI,
   SmallVectorImpl<MachineInstr *> &Worklist) const {
   for (MachineRegisterInfo::use_iterator I = MRI.use_begin(DstReg),
-         E = MRI.use_end(); I != E; ++I) {
+         E = MRI.use_end(); I != E;) {
     MachineInstr &UseMI = *I->getParent();
     if (!canReadVGPR(UseMI, I.getOperandNo())) {
       Worklist.push_back(&UseMI);
+
+      do {
+        ++I;
+      } while (I != E && I->getParent() == &UseMI);
+    } else {
+      ++I;
     }
   }
 }

diff --git a/test/CodeGen/AMDGPU/sminmax.ll b/test/CodeGen/AMDGPU/sminmax.ll
index 560d5597baa94c31151b3a71fceac60b97e5b38c..83465206e066278c6d2d9aa39fc13573902e311a 100644 (file)
--- a/test/CodeGen/AMDGPU/sminmax.ll
+++ b/test/CodeGen/AMDGPU/sminmax.ll
@@ -32,6 +32,20 @@ define void @v_abs_i32(i32 addrspace(1)* %out, i32 addrspace(1)* %src) nounwind
   ret void
 }
 
+; GCN-LABEL: {{^}}v_abs_i32_repeat_user:
+; GCN: v_sub_i32_e32 [[NEG:v[0-9]+]], vcc, 0, [[SRC:v[0-9]+]]
+; GCN: v_max_i32_e32 [[MAX:v[0-9]+]], [[NEG]], [[SRC]]
+; GCN: v_mul_lo_i32 v{{[0-9]+}}, [[MAX]], [[MAX]]
+define void @v_abs_i32_repeat_user(i32 addrspace(1)* %out, i32 addrspace(1)* %src) nounwind {
+  %val = load i32, i32 addrspace(1)* %src, align 4
+  %neg = sub i32 0, %val
+  %cond = icmp sgt i32 %val, %neg
+  %res = select i1 %cond, i32 %val, i32 %neg
+  %mul = mul i32 %res, %res
+  store i32 %mul, i32 addrspace(1)* %out, align 4
+  ret void
+}
+
 ; FUNC-LABEL: {{^}}s_abs_v2i32:
 ; GCN: s_abs_i32
 ; GCN: s_abs_i32