[llvm] [GISel] Combine shift + trunc + shift pattern (PR #155583)

[via llvm-commits]

================
@@ -1684,24 +1684,14 @@ define i32 @combine_i32_sdiv_const7(i32 %x) {
 }
 
 define i32 @combine_i32_sdiv_const100(i32 %x) {
-; CHECK-SD-LABEL: combine_i32_sdiv_const100:
-; CHECK-SD:       // %bb.0:
-; CHECK-SD-NEXT:    mov w8, #34079 // =0x851f
-; CHECK-SD-NEXT:    movk w8, #20971, lsl #16
-; CHECK-SD-NEXT:    smull x8, w0, w8
-; CHECK-SD-NEXT:    asr x8, x8, #37
-; CHECK-SD-NEXT:    add w0, w8, w8, lsr #31
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: combine_i32_sdiv_const100:
-; CHECK-GI:       // %bb.0:
-; CHECK-GI-NEXT:    mov w8, #34079 // =0x851f
-; CHECK-GI-NEXT:    movk w8, #20971, lsl #16
-; CHECK-GI-NEXT:    smull x8, w0, w8
-; CHECK-GI-NEXT:    asr x8, x8, #32
-; CHECK-GI-NEXT:    asr w8, w8, #5
-; CHECK-GI-NEXT:    add w0, w8, w8, lsr #31
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: combine_i32_sdiv_const100:
----------------
jyli0116 wrote:

Not for this specific pattern yet, I can add some specific tests for it

https://github.com/llvm/llvm-project/pull/155583