[llvm] [AMDGPU][GlobalISel] Add RegBankLegalize support for G_IS_FPCLASS (PR #167575)

[via llvm-commits]

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@@ -30,58 +30,132 @@ define amdgpu_kernel void @sgpr_isnan_f32(ptr addrspace(1) %out, float %x) {
 ; GFX7GLISEL-NEXT:    s_mov_b32 s2, -1
 ; GFX7GLISEL-NEXT:    s_waitcnt lgkmcnt(0)
 ; GFX7GLISEL-NEXT:    v_cmp_class_f32_e64 s[4:5], s3, 3
-; GFX7GLISEL-NEXT:    v_cndmask_b32_e64 v0, 0, -1, s[4:5]
+; GFX7GLISEL-NEXT:    s_or_b64 s[4:5], s[4:5], s[4:5]
+; GFX7GLISEL-NEXT:    s_cselect_b32 s3, 1, 0
+; GFX7GLISEL-NEXT:    s_and_b32 s3, s3, 1
+; GFX7GLISEL-NEXT:    s_cmp_lg_u32 s3, 0
+; GFX7GLISEL-NEXT:    s_cselect_b32 s3, -1, 0
+; GFX7GLISEL-NEXT:    v_mov_b32_e32 v0, s3
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vangthao95 wrote:

Added a fixme.

https://github.com/llvm/llvm-project/pull/167575