[llvm] [GlobalIsel] Combine freeze (PR #93239)

[Dhruv Chawla via llvm-commits]

Thorsten =?utf-8?q?Schütt?= <schuett at gmail.com>,
Thorsten =?utf-8?q?Schütt?= <schuett at gmail.com>,
Thorsten =?utf-8?q?Schütt?= <schuett at gmail.com>,
Thorsten =?utf-8?q?Schütt?= <schuett at gmail.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/93239 at github.com>


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@@ -0,0 +1,610 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -o - -mtriple=aarch64-unknown-unknown -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs %s | FileCheck %s
+
+...
+---
+name:            freeze_register
+body:             |
+  bb.1:
+    liveins: $w0
+
+    ; CHECK-LABEL: name: freeze_register
+    ; CHECK: liveins: $w0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s64) = COPY $x0
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s64) = G_FREEZE [[COPY]]
+    ; CHECK-NEXT: $x0 = COPY [[FREEZE]](s64)
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:_(s64) = COPY $x0
+    %2:_(s64) = G_FREEZE %0
+    $x0 = COPY %2(s64)
+    RET_ReallyLR implicit $x0
+
+...
+---
+name:            freeze_constant
+body:             |
+  bb.1:
+    liveins: $w0
+
+    ; CHECK-LABEL: name: freeze_constant
+    ; CHECK: liveins: $w0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 9
+    ; CHECK-NEXT: $x0 = COPY [[C]](s64)
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:_(s64) = COPY $x0
+    %1:_(s64) = G_CONSTANT i64 9
+    %2:_(s64) = G_FREEZE %1
+    $x0 = COPY %2(s64)
+    RET_ReallyLR implicit $x0
+
+...
+---
+name:            freeze_fconstant
+body:             |
+  bb.1:
+    liveins: $w0
+
+    ; CHECK-LABEL: name: freeze_fconstant
+    ; CHECK: liveins: $w0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s64) = G_FCONSTANT double 9.000000e+00
+    ; CHECK-NEXT: $x0 = COPY [[C]](s64)
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:_(s64) = COPY $x0
----------------
dc03-work wrote:

Dead instruction.

https://github.com/llvm/llvm-project/pull/93239