[llvm] [AMDGPU][True16][GlobalISel] Fix v2*16 build_vector patterns (PR #151496)

[Mirko Brkušanin via llvm-commits]

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@@ -1,8 +1,33 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 < %s | FileCheck -enable-var-scope -check-prefix=GFX9 %s
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=fiji < %s | FileCheck -enable-var-scope -check-prefix=GFX8 %s
+; RUN: llc -global-isel=0 -mtriple=amdgcn-amd-amdhsa -mcpu=fiji < %s | FileCheck -enable-var-scope -check-prefixes=GFX8,GFX8-SDAG %s
+; RUN: llc -global-isel=1 -mtriple=amdgcn-amd-amdhsa -mcpu=fiji < %s | FileCheck -enable-var-scope -check-prefixes=GFX8,GFX8-GISEL %s
+; RUN: llc -global-isel=0 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 < %s | FileCheck -enable-var-scope -check-prefixes=GFX9,GFX9-SDAG %s
+; RUN: llc -global-isel=1 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 < %s | FileCheck -enable-var-scope -check-prefixes=GFX9,GFX9-GISEL %s
+; RUN: llc -global-isel=0 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1100 -mattr=-real-true16 < %s | FileCheck -enable-var-scope -check-prefixes=GFX11,GFX11-FAKE,GFX11-FAKE16-SDAG %s
+; RUN: llc -global-isel=1 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1100 -mattr=-real-true16 < %s | FileCheck -enable-var-scope -check-prefixes=GFX11,GFX11-FAKE,GFX11-FAKE16-GISEL %s
+; RUN: llc -global-isel=0 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1100 -mattr=+real-true16 < %s | FileCheck -enable-var-scope -check-prefixes=GFX11,GFX11-TRUE,GFX11-TRUE16-SDAG %s
+; RUN: llc -global-isel=1 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1100 -mattr=+real-true16 < %s | FileCheck -enable-var-scope -check-prefixes=GFX11,GFX11-TRUE,GFX11-TRUE16-GISEL %s
 
 define void @undef_lo_v2i16(i16 %arg0) {
+; GFX8-SDAG-LABEL: undef_lo_v2i16:
+; GFX8-SDAG:       ; %bb.0:
+; GFX8-SDAG-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX8-SDAG-NEXT:    v_lshlrev_b32_e32 v0, 16, v0
+; GFX8-SDAG-NEXT:    ;;#ASMSTART
+; GFX8-SDAG-NEXT:    ; use v0
+; GFX8-SDAG-NEXT:    ;;#ASMEND
+; GFX8-SDAG-NEXT:    s_setpc_b64 s[30:31]
+;
+; GFX8-GISEL-LABEL: undef_lo_v2i16:
+; GFX8-GISEL:       ; %bb.0:
+; GFX8-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX8-GISEL-NEXT:    v_and_b32_e32 v0, 0xffff, v0
+; GFX8-GISEL-NEXT:    v_lshlrev_b32_e32 v0, 16, v0
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mbrkusanin wrote:

Difference here between SDAG and GlobalISel for GFX8 looks like a legalizer issue. GFX8 makes different choices because of hasVOP3P check

https://github.com/llvm/llvm-project/pull/151496