[llvm] [GlobalISel][ARM] legalize G_FPENV_RESET for soft-float mode (PR #81456)

[Serge Pavlov via llvm-commits]

https://github.com/spavloff created https://github.com/llvm/llvm-project/pull/81456

None

>From 9c5771852c7ca7ffcb3442c4bc5bc5ddd417e2ee Mon Sep 17 00:00:00 2001
From: Serge Pavlov <sepavloff at gmail.com>
Date: Mon, 12 Feb 2024 16:00:15 +0700
Subject: [PATCH] [GlobalISel][ARM] legalize G_FPENV_RESET for soft-float mode

---
 llvm/lib/Target/ARM/ARMLegalizerInfo.cpp  |  3 ++-
 llvm/test/CodeGen/ARM/GlobalISel/fpenv.ll | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
index 67187c4b1b3ae7..c5199aab752726 100644
--- a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
@@ -223,7 +223,8 @@ ARMLegalizerInfo::ARMLegalizerInfo(const ARMSubtarget &ST) {
     getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
         .libcallForCartesianProduct({s32, s64}, {s32});
 
-    getActionDefinitionsBuilder({G_GET_FPENV, G_SET_FPENV}).libcall();
+    getActionDefinitionsBuilder({G_GET_FPENV, G_SET_FPENV, G_RESET_FPENV})
+        .libcall();
   }
 
   // Just expand whatever loads and stores are left.
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/fpenv.ll b/llvm/test/CodeGen/ARM/GlobalISel/fpenv.ll
index 3d18a65bd43452..f5aea62d4be79a 100644
--- a/llvm/test/CodeGen/ARM/GlobalISel/fpenv.ll
+++ b/llvm/test/CodeGen/ARM/GlobalISel/fpenv.ll
@@ -74,5 +74,19 @@ entry:
   ret void
 }
 
+define void @func_reset_soft() #0 {
+; CHECK-LABEL: func_reset_soft:
+; CHECK:       @ %bb.0: @ %entry
+; CHECK-NEXT:    .save {r11, lr}
+; CHECK-NEXT:    push {r11, lr}
+; CHECK-NEXT:    mvn r0, #0
+; CHECK-NEXT:    bl fesetenv
+; CHECK-NEXT:    pop {r11, lr}
+; CHECK-NEXT:    mov pc, lr
+entry:
+  call void @llvm.reset.fpenv()
+  ret void
+}
+
 attributes #0 = { nounwind "use-soft-float"="true" }