[llvm] [CodeGen] Add preliminary plumbing for `samesign` flag (PR #112354)

[Thorsten Schütt via llvm-commits]

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@@ -0,0 +1,40 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -x mir -march=x86-64 -run-pass=none -verify-machineinstrs %s -o - | FileCheck %s
+
+--- |
+
+  define i1 @icmp_samesign(i32 %a, i32 %b) {
+  entry:
+    %res = icmp samesign ult i32 %a, %b
+    ret i1 %res
+  }
+
+...
+---
+name:            icmp_samesign
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gr32 }
+  - { id: 1, class: gr32 }
+liveins:
+  - { reg: '$edi', virtual-reg: '%0' }
+  - { reg: '$esi', virtual-reg: '%1' }
+body:             |
+  bb.0:
+    liveins: $edi, $esi
+
+    ; CHECK-LABEL: name: icmp_samesign
+    ; CHECK: liveins: $edi, $esi
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %tmp0:_(s32) = COPY $edi
+    ; CHECK-NEXT: %tmp1:_(s32) = COPY $esi
+    ; CHECK-NEXT: %tmp4:_(s8) = samesign G_ICMP intpred(ult), %tmp0(s32), %tmp1
+    ; CHECK-NEXT: $al = COPY %tmp4(s8)
+    ; CHECK-NEXT: RET 0, implicit $al
+    %tmp0:_(s32) = COPY $edi
+    %tmp1:_(s32) = COPY $esi
+    %tmp4:_(s8) = samesign G_ICMP intpred(ult), %tmp0(s32), %tmp1
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tschuett wrote:

Again no test without `samesign` .

https://github.com/llvm/llvm-project/pull/112354