Fix PromoteInt8Type hang when promoteInst is ptrtoint

A ptrtoint instruction is added as candidate to be promoted, however,
it isn't handled in the while loop of promoteInstructions. This causes
the loop hanging later when processing its user instruction, which is
also to be promoted.

Author: wenju-he

IGC/Compiler/CISACodeGen/PromoteInt8Type.cpp

@@ -663,6 +663,7 @@ void PromoteInt8Type::promoteInstructions()
                     break;
                 }
                 case Instruction::BitCast:
+                case Instruction::PtrToInt:
                 case Instruction::Load:
                 case Instruction::Trunc:
                 case Instruction::Call:

IGC/Compiler/tests/PromoteInt8Type/basic.ll

@@ -163,3 +163,15 @@ define i1 @test_icmp(i8 %src1, i8 %src2) {
   ret i1 %1
 }
 
+define i8 @test_ptrtoint(i8* %src) {
+; CHECK-LABEL: @test_ptrtoint(
+; CHECK:    [[P2B:%.*]] = ptrtoint i8* %src to i8
+; CHECK:    [[B2S:%.*]] = sext i8 [[P2B]] to i16
+; CHECK:    [[AND:%.*]] = and i16 [[B2S]], 7
+; CHECK:    [[TRUNC:%.*]] = trunc i16 [[AND]] to i8
+; CHECK:    ret i8 [[TRUNC]]
+
+  %1 = ptrtoint i8* %src to i8
+  %2 = and i8 %1, 7
+  ret i8 %2
+}