[NFC][NVPTX][test] Update test for fneg half

[justinfargnoli]

test_fneg function uses fsub half 0.0, %x. Add a test that uses the fneg instruction directly.

[llvmbot]

@llvm/pr-subscribers-backend-nvptx

Author: Justin Fargnoli (justinfargnoli)

Changes

test_fneg function uses fsub half 0.0, %x. Add a test that uses the fneg instruction directly.

---

Full diff: https://github.com/llvm/llvm-project/pull/95856.diff

1 Files Affected:

• (modified) llvm/test/CodeGen/NVPTX/f16-instructions.ll (+13-3)

diff --git a/llvm/test/CodeGen/NVPTX/f16-instructions.ll b/llvm/test/CodeGen/NVPTX/f16-instructions.ll
index deea2e3b557f1..e1c50b3982417 100644
--- a/llvm/test/CodeGen/NVPTX/f16-instructions.ll
+++ b/llvm/test/CodeGen/NVPTX/f16-instructions.ll
@@ -131,8 +131,8 @@ define half @test_fsub(half %a, half %b) #0 {
   ret half %r
 }
 
-; CHECK-LABEL: test_fneg(
-; CHECK-DAG:  ld.param.b16    [[A:%rs[0-9]+]], [test_fneg_param_0];
+; CHECK-LABEL: test_old_fneg(
+; CHECK-DAG:  ld.param.b16    [[A:%rs[0-9]+]], [test_old_fneg_param_0];
 ; CHECK-F16-NOFTZ-NEXT:   mov.b16        [[Z:%rs[0-9]+]], 0x0000
 ; CHECK-F16-NOFTZ-NEXT:   sub.rn.f16     [[R:%rs[0-9]+]], [[Z]], [[A]];
 ; CHECK-F16-FTZ-NEXT:   mov.b16        [[Z:%rs[0-9]+]], 0x0000
@@ -143,11 +143,21 @@ define half @test_fsub(half %a, half %b) #0 {
 ; CHECK-NOF16-NEXT: cvt.rn.f16.f32 [[R:%rs[0-9]+]], [[R32]]
 ; CHECK-NEXT: st.param.b16    [func_retval0+0], [[R]];
 ; CHECK-NEXT: ret;
-define half @test_fneg(half %a) #0 {
+define half @test_old_fneg(half %a) #0 {
   %r = fsub half 0.0, %a
   ret half %r
 }
 
+; CHECK-LABEL: test_fneg(
+; CHECK-DAG:  ld.param.b16    [[A:%rs[0-9]+]], [test_fneg_param_0];
+; CHECK-NEXT: xor.b16    [[R:%rs[0-9]+]], [[A]], -32768;
+; CHECK-NEXT: st.param.b16    [func_retval0+0], [[R]];
+; CHECK-NEXT: ret;
+define half @test_fneg(half %a) #0 {
+  %r = fneg half %a
+  ret half %r
+}
+
 ; CHECK-LABEL: test_fmul(
 ; CHECK-DAG:  ld.param.b16    [[A:%rs[0-9]+]], [test_fmul_param_0];
 ; CHECK-DAG:  ld.param.b16    [[B:%rs[0-9]+]], [test_fmul_param_1];

[jlebar]

Nit, what does a single CHECK-DAG mean? I thought this was only meaningful if you had two or more of them. https://llvm.org/docs/CommandGuide/FileCheck.html#the-check-dag-directive

[justinfargnoli]

Thanks for pointing this out. This was an artifact from my copy/paste. It should be fixed with 5da6544.