# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 6 # RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1250 -amdgpu-s-branch-bits=4 -run-pass branch-relaxation %s -o - | FileCheck %s # Test that getInstSizeInBytes correctly estimates S_MOV_B64 with 64-bit # literal values on targets with 64-bit literal support (gfx1250). # # Values outside [0, 2^31-1] require 64-bit literal encoding, making the # instruction 12 bytes (4-byte opcode + 8-byte literal) instead of 8 bytes # (4-byte opcode + 4-byte literal). # # With -amdgpu-s-branch-bits=4, forward branches can reach at most +7 dwords. # Three S_MOV_B64 with 64-bit literals = 3 * 12 = 36 bytes = 9 dwords, # which exceeds the 7-dword limit, so the branch must be relaxed. # # Without the correct size estimation (8 bytes instead of 12), the total # would be 3 * 8 = 24 bytes = 6 dwords, fitting within the limit, and # relaxation would not occur. In a rare real-world scenario, this could lead to # an assembler error where branch size exceeds simm16. # The branch is relaxed: the original S_CBRANCH_SCC0 is inverted to # S_CBRANCH_SCC1 (skipping the long branch), and a new block (bb.3) is # inserted with S_ADD_PC_I64 for the long branch. --- name: s_mov_b64_64bit_literal_size tracksRegLiveness: true machineFunctionInfo: scratchRSrcReg: '$sgpr0_sgpr1_sgpr2_sgpr3' stackPtrOffsetReg: '$sgpr32' body: | ; CHECK-LABEL: name: s_mov_b64_64bit_literal_size ; CHECK: bb.0: ; CHECK-NEXT: successors: %bb.3(0x40000000), %bb.1(0x40000000) ; CHECK-NEXT: liveins: $sgpr8 ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: S_CMP_EQ_U32 $sgpr8, 0, implicit-def $scc ; CHECK-NEXT: S_CBRANCH_SCC1 %bb.1, implicit $scc ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: bb.3: ; CHECK-NEXT: successors: %bb.2(0x80000000) ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: $sgpr4_sgpr5 = S_GETPC_B64 post-instr-symbol ; CHECK-NEXT: $sgpr4 = S_ADD_U32 $sgpr4, target-flags() , implicit-def $scc ; CHECK-NEXT: $sgpr5 = S_ADDC_U32 $sgpr5, target-flags() , implicit-def $scc, implicit $scc ; CHECK-NEXT: S_SETPC_B64 $sgpr4_sgpr5 ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: bb.1: ; CHECK-NEXT: successors: %bb.2(0x80000000) ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: $sgpr10_sgpr11 = S_MOV_B64 4294967295 ; CHECK-NEXT: $sgpr12_sgpr13 = S_MOV_B64 2147483648 ; CHECK-NEXT: $sgpr14_sgpr15 = S_MOV_B64 -17 ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: bb.2: ; CHECK-NEXT: S_ENDPGM 0 bb.0: liveins: $sgpr8 S_CMP_EQ_U32 $sgpr8, 0, implicit-def $scc S_CBRANCH_SCC0 %bb.2, implicit $scc bb.1: ; S_MOV_B64 with values requiring 64-bit literal encoding (12 bytes each). ; These values are outside the [0, 2^31-1] range where 32-bit literal ; can be used, so they need 64-bit literal encoding on gfx1250. ; 0xFFFFFFFF (4294967295) is in [2^31, 2^32-1]. ; 0x80000000 (2147483648) is exactly 2^31. ; -17 (0xFFFFFFFFFFFFFFEF) is a negative non-inline constant. $sgpr10_sgpr11 = S_MOV_B64 4294967295 $sgpr12_sgpr13 = S_MOV_B64 2147483648 $sgpr14_sgpr15 = S_MOV_B64 -17 bb.2: S_ENDPGM 0 ...