# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5 # RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1010 -run-pass=si-fold-operands -o - %s | FileCheck --check-prefix=GCN %s # Constant-folding of scalar S_ADD_I32 / S_ADD_U32 / S_SUB_I32 / S_SUB_U32 in # SIFoldOperands::tryConstantFoldOp: # # * (imm, imm) folds to S_MOV_B32 of the precomputed value # * (x, 0) and (0, x) for ADD fold to a copy of x # * (x, 0) for SUB folds to a copy of x; (0, x) does NOT fold (negation) # * Folding is gated by allImplicitDefsAreDead, so when the SCC def is live # the instruction must be left untouched. # In each imm-imm case below, the immediate K is materialised by an upstream # S_MOV_B32 and folded into the SOP2 by tryFoldFoldableCopy; that triggers # tryConstantFoldOp, which then collapses the (imm, imm) SOP2 into a single # S_MOV_B32 via the new evalBinaryInstruction handlers. --- name: s_add_i32_imm_imm_scc_dead tracksRegLiveness: true body: | bb.0: ; GCN-LABEL: name: s_add_i32_imm_imm_scc_dead ; GCN: [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 12345 ; GCN-NEXT: S_ENDPGM 0, implicit [[S_MOV_B32_]] %0:sreg_32 = S_MOV_B32 12345 %1:sreg_32 = S_ADD_I32 0, %0, implicit-def dead $scc S_ENDPGM 0, implicit %1 ... --- name: s_add_u32_imm_imm_scc_dead tracksRegLiveness: true body: | bb.0: ; GCN-LABEL: name: s_add_u32_imm_imm_scc_dead ; GCN: [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 99 ; GCN-NEXT: S_ENDPGM 0, implicit [[S_MOV_B32_]] %0:sreg_32 = S_MOV_B32 49 %1:sreg_32 = S_ADD_U32 50, %0, implicit-def dead $scc S_ENDPGM 0, implicit %1 ... --- name: s_sub_i32_imm_imm_scc_dead tracksRegLiveness: true body: | bb.0: ; GCN-LABEL: name: s_sub_i32_imm_imm_scc_dead ; GCN: [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 43 ; GCN-NEXT: S_ENDPGM 0, implicit [[S_MOV_B32_]] %0:sreg_32 = S_MOV_B32 7 %1:sreg_32 = S_SUB_I32 50, %0, implicit-def dead $scc S_ENDPGM 0, implicit %1 ... --- name: s_sub_u32_imm_imm_scc_dead tracksRegLiveness: true body: | bb.0: ; GCN-LABEL: name: s_sub_u32_imm_imm_scc_dead ; GCN: [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 92 ; GCN-NEXT: S_ENDPGM 0, implicit [[S_MOV_B32_]] %0:sreg_32 = S_MOV_B32 7 %1:sreg_32 = S_SUB_U32 99, %0, implicit-def dead $scc S_ENDPGM 0, implicit %1 ... # In each (reg, 0) / (0, reg) case below, the zero is materialised by an # upstream S_MOV_B32 0 and folded into the SOP2 by tryFoldFoldableCopy; that # triggers tryConstantFoldOp, which then takes the new add/sub branch and # collapses the SOP2 to a COPY of the non-zero operand (or, for `0 - x`, # correctly leaves the SOP2 untouched). --- name: s_add_i32_reg_zero tracksRegLiveness: true body: | bb.0: liveins: $sgpr0 ; GCN-LABEL: name: s_add_i32_reg_zero ; GCN: liveins: $sgpr0 ; GCN-NEXT: {{ $}} ; GCN-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY $sgpr0 ; GCN-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[COPY]] ; GCN-NEXT: S_ENDPGM 0, implicit [[COPY1]] %0:sreg_32 = COPY $sgpr0 %1:sreg_32 = S_MOV_B32 0 %2:sreg_32 = S_ADD_I32 %0, %1, implicit-def dead $scc S_ENDPGM 0, implicit %2 ... --- name: s_add_i32_zero_reg tracksRegLiveness: true body: | bb.0: liveins: $sgpr0 ; GCN-LABEL: name: s_add_i32_zero_reg ; GCN: liveins: $sgpr0 ; GCN-NEXT: {{ $}} ; GCN-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY $sgpr0 ; GCN-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[COPY]] ; GCN-NEXT: S_ENDPGM 0, implicit [[COPY1]] %0:sreg_32 = COPY $sgpr0 %1:sreg_32 = S_MOV_B32 0 %2:sreg_32 = S_ADD_I32 %1, %0, implicit-def dead $scc S_ENDPGM 0, implicit %2 ... --- name: s_sub_i32_reg_zero tracksRegLiveness: true body: | bb.0: liveins: $sgpr0 ; GCN-LABEL: name: s_sub_i32_reg_zero ; GCN: liveins: $sgpr0 ; GCN-NEXT: {{ $}} ; GCN-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY $sgpr0 ; GCN-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[COPY]] ; GCN-NEXT: S_ENDPGM 0, implicit [[COPY1]] %0:sreg_32 = COPY $sgpr0 %1:sreg_32 = S_MOV_B32 0 %2:sreg_32 = S_SUB_I32 %0, %1, implicit-def dead $scc S_ENDPGM 0, implicit %2 ... # S_SUB_I32 0, %x is *negation*, not a copy. Must NOT fold to a copy. --- name: s_sub_i32_zero_reg_must_not_fold tracksRegLiveness: true body: | bb.0: liveins: $sgpr0 ; GCN-LABEL: name: s_sub_i32_zero_reg_must_not_fold ; GCN: liveins: $sgpr0 ; GCN-NEXT: {{ $}} ; GCN-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY $sgpr0 ; GCN-NEXT: [[S_SUB_I32_:%[0-9]+]]:sreg_32 = S_SUB_I32 0, [[COPY]], implicit-def dead $scc ; GCN-NEXT: S_ENDPGM 0, implicit [[S_SUB_I32_]] %0:sreg_32 = COPY $sgpr0 %1:sreg_32 = S_MOV_B32 0 %2:sreg_32 = S_SUB_I32 %1, %0, implicit-def dead $scc S_ENDPGM 0, implicit %2 ... # SCC live: tryFoldFoldableCopy still folds the upstream MOV's immediate into # the SOP2's source, but tryConstantFoldOp's allImplicitDefsAreDead gate must # reject the (imm, imm) -> S_MOV_B32 collapse since the carry-out is needed. --- name: s_add_i32_imm_imm_scc_live_must_not_fold tracksRegLiveness: true body: | bb.0: ; GCN-LABEL: name: s_add_i32_imm_imm_scc_live_must_not_fold ; GCN: [[S_ADD_I32_:%[0-9]+]]:sreg_32 = S_ADD_I32 0, 99, implicit-def $scc ; GCN-NEXT: S_ENDPGM 0, implicit [[S_ADD_I32_]], implicit $scc %0:sreg_32 = S_MOV_B32 99 %1:sreg_32 = S_ADD_I32 0, %0, implicit-def $scc S_ENDPGM 0, implicit %1, implicit $scc ...