[llvm-branch-commits] [llvm] AMDGPU/GlobalISel: add RegBankLegalize rules for extends and trunc (PR #132383)

[Nicolai Hähnle via llvm-branch-commits]

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@@ -233,8 +222,13 @@ body: |
     ; CHECK: liveins: $vgpr0
     ; CHECK-NEXT: {{  $}}
     ; CHECK-NEXT: [[COPY:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
-    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:vgpr(s1) = G_TRUNC [[COPY]](s32)
-    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:vgpr(s16) = G_ANYEXT [[TRUNC]](s1)
+    ; CHECK-NEXT: [[C:%[0-9]+]]:vgpr(s32) = G_CONSTANT i32 1
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:vgpr(s32) = G_AND [[COPY]], [[C]]
+    ; CHECK-NEXT: [[C1:%[0-9]+]]:vgpr(s32) = G_CONSTANT i32 0
+    ; CHECK-NEXT: [[ICMP:%[0-9]+]]:vcc(s1) = G_ICMP intpred(ne), [[AND]](s32), [[C1]]
+    ; CHECK-NEXT: [[C2:%[0-9]+]]:vgpr(s16) = G_CONSTANT i16 1
+    ; CHECK-NEXT: [[C3:%[0-9]+]]:vgpr(s16) = G_CONSTANT i16 0
+    ; CHECK-NEXT: [[SELECT:%[0-9]+]]:vgpr(s16) = G_SELECT [[ICMP]](s1), [[C2]], [[C3]]
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nhaehnle wrote:

This is unnecessarily convoluted. A single `G_TRUNC` should do the trick. (Isn't that something a combiner could do?)

https://github.com/llvm/llvm-project/pull/132383