[CGP] Add pre-commit test for Fix matching of uadd overflow

Add tests where uadd overflow intrinsic is matched for:
`Add = add A,(uint64_t)-1; Cmp = icmp ne A, 0`
instead of:
`Add = add A,-1; Cmp = icmp ne A, 0`
where -1 is represented in 256 bits.

Signed-off-by: Vladimir Radosavljevic <[email protected]>

Author: vladimirradosavljevic

llvm/test/CodeGen/EraVM/cgp-uadd-overflow-wrong-match.ll

@@ -0,0 +1,48 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 2
+; RUN: llc -O3 < %s | FileCheck %s
+
+target datalayout = "E-p:256:256-i256:256:256-S32-a:256:256"
+target triple = "eravm"
+
+define i256 @dont_match(i256 %a) {
+; CHECK-LABEL: dont_match:
+; CHECK:       ; %bb.0: ; %entry
+; CHECK-NEXT:    add r1, r0, r2
+; CHECK-NEXT:    add @CPI0_0[0], r2, r1
+; CHECK-NEXT:    add! @CPI0_0[0], r2, r2
+; CHECK-NEXT:    jump.lt @.BB0_2
+; CHECK-NEXT:  ; %bb.1: ; %else
+; CHECK-NEXT:    ret
+; CHECK-NEXT:  .BB0_2: ; %then
+; CHECK-NEXT:    add r0, r0, r1
+; CHECK-NEXT:    ret
+entry:
+  %add = add i256 %a, 18446744073709551615
+  %cmp = icmp ne i256 %a, 0
+  br i1 %cmp, label %then, label %else
+
+then:
+  ret i256 0
+
+else:
+  ret i256 %add
+}
+
+define i256 @match(i256 %a) {
+; CHECK-LABEL: match:
+; CHECK:       ; %bb.0: ; %entry
+; CHECK-NEXT:    sub! r1, r0, r2
+; CHECK-NEXT:    sub.s.eq 1, r1, r1
+; CHECK-NEXT:    add.ne r0, r0, r1
+; CHECK-NEXT:    ret
+entry:
+  %add = add i256 %a, -1
+  %cmp = icmp ne i256 %a, 0
+  br i1 %cmp, label %then, label %else
+
+then:
+  ret i256 0
+
+else:
+  ret i256 %add
+}