[llvm] stop emitting direct copy from intermediate result to out reg (PR #135326)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,87 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=amdgcn -mcpu=gfx1100 | FileCheck %s -check-prefixes=GFX11
+
+define amdgpu_ps float @uniform_fpext(half inreg %x) {
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arsenm wrote:

Test filename isn't right, this isn't about fixing illegal copies. The function test names also aren't really right, this is about returning uniform VGPRs in SGPRs 

https://github.com/llvm/llvm-project/pull/135326