AMDGPU/GlobalISel: Fix non-power-of-2 G_EXTRACT sources

[arsenm]

Fix not calling observer

[paquette]

lib/CodeGen/GlobalISel/LegalizerHelper.cpp

909

Why UnableToLegalize?

[arsenm]

Fix UnableToLegalize

[paquette]

LGTM

[arsenm]

r358892

lib/CodeGen/GlobalISel/LegalizerHelper.cpp

if (TypeIdx == 0) {
 
     auto LShr = MIRBuilder.buildLShr(
       ShiftTy, Src, MIRBuilder.buildConstant(ShiftTy, Offset));
     MIRBuilder.buildTrunc(DstReg, LShr);
     MI.eraseFromParent();
     return Legalized;
   }
 
+  if (SrcTy.isScalar()) {
+    Observer.changingInstr(MI);
+    widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
+    Observer.changedInstr(MI);
+    return Legalized;
+  }
+
   if (!SrcTy.isVector())
     return UnableToLegalize;
 
   if (DstTy != SrcTy.getElementType())
     return UnableToLegalize;
 
   if (Offset % SrcTy.getScalarSizeInBits() != 0)
     return UnableToLegalize;

test/CodeGen/AMDGPU/GlobalISel/legalize-extract.mir

 
 ---
 name: test_extract_s1_s8_offset0
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: test_extract_s1_s8_offset0
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[TRUNC:%[0-9]+]]:_(s8) = G_TRUNC [[COPY]](s32)
-    ; CHECK: [[EXTRACT:%[0-9]+]]:_(s1) = G_EXTRACT [[TRUNC]](s8), 0
-    ; CHECK: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[EXTRACT]](s1)
-    ; CHECK: $vgpr0 = COPY [[ANYEXT]](s32)
+    ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY [[COPY]](s32)
+    ; CHECK: $vgpr0 = COPY [[COPY1]](s32)
     %0:_(s32) = COPY $vgpr0
     %1:_(s8) = G_TRUNC %0
     %2:_(s1) = G_EXTRACT %1, 0
     %3:_(s32) = G_ANYEXT %2
     $vgpr0 = COPY %3
 ...
 
 ---
 name: test_extract_s1_s8_offset2
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: test_extract_s1_s8_offset2
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[TRUNC:%[0-9]+]]:_(s8) = G_TRUNC [[COPY]](s32)
-    ; CHECK: [[EXTRACT:%[0-9]+]]:_(s1) = G_EXTRACT [[TRUNC]](s8), 2
-    ; CHECK: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[EXTRACT]](s1)
+    ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[COPY]](s32)
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
+    ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[C]](s32)
+    ; CHECK: [[LSHR:%[0-9]+]]:_(s16) = G_LSHR [[TRUNC]], [[TRUNC1]](s16)
+    ; CHECK: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[LSHR]](s16)
     ; CHECK: $vgpr0 = COPY [[ANYEXT]](s32)
     %0:_(s32) = COPY $vgpr0
     %1:_(s8) = G_TRUNC %0
     %2:_(s1) = G_EXTRACT %1, 2
     %3:_(s32) = G_ANYEXT %2
     $vgpr0 = COPY %3
 ...