[PATCH] R600/SI: Fix bug in SIInstrInfo::legalizeOpWithMove()

[Michel Dänzer]

On 04.09.2014 06:38, Tom Stellard wrote:
> We must constrain the destination register class of legalized operands
> to a VGPR class or else the illegal operand may be folded back into
> the instruction by the register coalescer.
> 
> This fixes a bug in add.ll that will be uncovered by future commits.

This patch currently breaks make check, see below. It's related to
Matthew's 'Try to keep i32 mul on SALU' change, which also broke two
piglit tests for me (more on that later). With that patch reverted, this
patch seems to work fine.


FAIL: LLVM :: CodeGen/R600/mul.ll (3277 of 11533)
******************** TEST 'LLVM :: CodeGen/R600/mul.ll' FAILED ********************
Script:
--
/home/daenzer/src/llvm-git/llvm/build-amd64/Release+Debug+Asserts/bin/llc -march=r600 -mcpu=redwood < /home/daenzer/src/llvm-git/llvm/test/CodeGen/R600/mul.ll | /home/daenzer/src/llvm-git/llvm/build-amd64/Release+Debug+Asserts/bin/FileCheck -check-prefix=EG /home/daenzer/src/llvm-git/llvm/test/CodeGen/R600/mul.ll -check-prefix=FUNC
/home/daenzer/src/llvm-git/llvm/build-amd64/Release+Debug+Asserts/bin/llc -march=r600 -mcpu=verde -verify-machineinstrs < /home/daenzer/src/llvm-git/llvm/test/CodeGen/R600/mul.ll | /home/daenzer/src/llvm-git/llvm/build-amd64/Release+Debug+Asserts/bin/FileCheck -check-prefix=SI -check-prefix=FUNC /home/daenzer/src/llvm-git/llvm/test/CodeGen/R600/mul.ll
--
Exit Code: 1

Command Output (stderr):
--

# After Register Allocation, before rewriter
# Machine code for function v_mul64_sext_c: Post SSA
Function Live Ins: %SGPR0_SGPR1 in %vreg0

0B	BB#0: derived from LLVM BB %0
	    Live Ins: %SGPR0_SGPR1
16B		%vreg0<def> = COPY %SGPR0_SGPR1; SReg_64:%vreg0
32B		%vreg23:sub0_sub1<def,read-undef> = S_LOAD_DWORDX2_IMM %vreg0, 9; mem:LD8[undef(addrspace=2)](nontemporal) SReg_128:%vreg23 SReg_64:%vreg0
48B		%vreg6:sub0_sub1<def,read-undef> = S_LOAD_DWORDX2_IMM %vreg0, 11; mem:LD8[undef(addrspace=2)](nontemporal) SReg_128:%vreg6 SReg_64:%vreg0
96B		%vreg6:sub2<def> = S_MOV_B32 -1; SReg_128:%vreg6
112B		%vreg6:sub3<def> = S_MOV_B32 61440; SReg_128:%vreg6
192B		%vreg7<def> = BUFFER_LOAD_DWORD_OFFSET %vreg6, 0, 0, 0, 0, 0, %EXEC<imp-use>; mem:LD4[%in(addrspace=1)] VGPR_32:%vreg7 SReg_128:%vreg6
208B		%vreg31<def> = S_MOV_B32 80; VReg_32:%vreg31
224B		%vreg34:sub0<def,read-undef> = V_MUL_LO_I32 %vreg7, %vreg31, %EXEC<imp-use>; VReg_64:%vreg34 VGPR_32:%vreg7 VReg_32:%vreg31
256B		%vreg12<def> = S_MOV_B32 0; SReg_32:%vreg12
288B		%vreg34:sub1<def> = COPY %vreg12; VReg_64:%vreg34 SReg_32:%vreg12
304B		%vreg14<def> = S_MOV_B32 80; SReg_32:%vreg14
320B		%vreg53:sub0<def,read-undef> = V_MUL_HI_I32 %vreg7, %vreg14, %EXEC<imp-use>; VReg_64:%vreg53 VGPR_32:%vreg7 SReg_32:%vreg14
368B		%vreg53:sub1<def> = COPY %vreg12; VReg_64:%vreg53 SReg_32:%vreg12
384B		%vreg55<def> = V_LSHL_B64 %vreg53, 32, %EXEC<imp-use>; VReg_64:%vreg55,%vreg53
464B		%vreg47:sub0<def,read-undef> = V_OR_B32_e32 %vreg55:sub0, %vreg34:sub0, %EXEC<imp-use>; VReg_64:%vreg47,%vreg55,%vreg34
544B		%vreg47:sub1<def> = V_OR_B32_e32 %vreg55:sub1, %vreg34:sub1, %EXEC<imp-use>; VReg_64:%vreg47,%vreg55,%vreg34
656B		%vreg23:sub2<def> = COPY %vreg6:sub2; SReg_128:%vreg23,%vreg6
672B		%vreg23:sub3<def> = COPY %vreg6:sub3; SReg_128:%vreg23,%vreg6
704B		BUFFER_STORE_DWORDX2_OFFSET %vreg47, %vreg23, 0, 0, 0, 0, 0, %EXEC<imp-use>; mem:ST8[%out(addrspace=1)] VReg_64:%vreg47 SReg_128:%vreg23
720B		S_ENDPGM

# End machine code for function v_mul64_sext_c.

*** Bad machine code: Illegal virtual register for instruction ***
- function:    v_mul64_sext_c
- basic block: BB#0  (0x203de10) [0B;736B)
- instruction: 208B	%vreg31<def> = S_MOV_B32 80; VReg_32:%vreg31
- operand 0:   %vreg31<def>
Expected a SReg_32 register, but got a VReg_32 register
LLVM ERROR: Found 1 machine code errors.
/home/daenzer/src/llvm-git/llvm/test/CodeGen/R600/mul.ll:83:15: error: expected string not found in input
; FUNC-LABEL: @v_mul64_sext_c:
              ^
<stdin>:134:16: note: scanning from here
 ;@mul64_sext_c:
               ^
<stdin>:142:2: note: possible intended match here
 .text
 ^



-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer