04fff547e2
Currently the return address ABI registers s[30:31], which fall in the call clobbered register range, are added as a live-in on the function entry to preserve its value when we have calls so that it gets saved and restored around the calls. But the DWARF unwind information (CFI) needs to track where the return address resides in a frame and the above approach makes it difficult to track the return address when the CFI information is emitted during the frame lowering, due to the involvment of understanding the control flow. This patch moves the return address ABI registers s[30:31] into callee saved registers range and stops adding live-in for return address registers, so that the CFI machinery will know where the return address resides when CSR save/restore happen during the frame lowering. And doing the above poses an issue that now the return instruction uses undefined register `sgpr30_sgpr31`. This is resolved by hiding the return address register use by the return instruction through the `SI_RETURN` pseudo instruction, which doesn't take any input operands, until the `SI_RETURN` pseudo gets lowered to the `S_SETPC_B64_return` during the `expandPostRAPseudo()`. As an added benefit, this patch simplifies overall return instruction handling. Note: The AMDGPU CFI changes are there only in the downstream code and another version of this patch will be posted for review for the downstream code. Reviewed By: arsenm, ronlieb Differential Revision: https://reviews.llvm.org/D114652
70 lines
4.8 KiB
LLVM
70 lines
4.8 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
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; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -stop-after=finalize-isel -o - %s | FileCheck -check-prefix=GCN %s
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; Make sure nofpexcept flags are emitted when lowering a
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; non-constrained fdiv.
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define float @fdiv_f32(float %a, float %b) #0 {
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; GCN-LABEL: name: fdiv_f32
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; GCN: bb.0.entry:
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; GCN-NEXT: liveins: $vgpr0, $vgpr1
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; GCN-NEXT: {{ $}}
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; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr1
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; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr0
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; GCN-NEXT: %4:vgpr_32, %5:sreg_64 = nofpexcept V_DIV_SCALE_F32_e64 0, [[COPY1]], 0, [[COPY]], 0, [[COPY1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %6:vgpr_32, %7:sreg_64 = nofpexcept V_DIV_SCALE_F32_e64 0, [[COPY]], 0, [[COPY]], 0, [[COPY1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %8:vgpr_32 = nofpexcept V_RCP_F32_e64 0, %6, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 3
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; GCN-NEXT: [[S_MOV_B32_1:%[0-9]+]]:sgpr_32 = S_MOV_B32 1065353216
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; GCN-NEXT: [[S_MOV_B32_2:%[0-9]+]]:sreg_32 = S_MOV_B32 0
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; GCN-NEXT: S_SETREG_B32_mode killed [[S_MOV_B32_]], 2305, implicit-def $mode, implicit $mode
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; GCN-NEXT: %12:vgpr_32 = nofpexcept V_FMA_F32_e64 1, %6, 0, %8, 0, killed [[S_MOV_B32_1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %13:vgpr_32 = nofpexcept V_FMA_F32_e64 0, killed %12, 0, %8, 0, %8, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %14:vgpr_32 = nofpexcept V_MUL_F32_e64 0, %4, 0, %13, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %15:vgpr_32 = nofpexcept V_FMA_F32_e64 1, %6, 0, %14, 0, %4, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %16:vgpr_32 = nofpexcept V_FMA_F32_e64 0, killed %15, 0, %13, 0, %14, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %17:vgpr_32 = nofpexcept V_FMA_F32_e64 1, %6, 0, %16, 0, %4, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: S_SETREG_B32_mode killed [[S_MOV_B32_2]], 2305, implicit-def dead $mode, implicit $mode
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; GCN-NEXT: $vcc = COPY %5
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; GCN-NEXT: %18:vgpr_32 = nofpexcept V_DIV_FMAS_F32_e64 0, killed %17, 0, %13, 0, %16, 0, 0, implicit $mode, implicit $vcc, implicit $exec
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; GCN-NEXT: %19:vgpr_32 = nofpexcept V_DIV_FIXUP_F32_e64 0, killed %18, 0, [[COPY]], 0, [[COPY1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: $vgpr0 = COPY %19
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; GCN-NEXT: SI_RETURN implicit $vgpr0
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entry:
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%fdiv = fdiv float %a, %b
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ret float %fdiv
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}
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define float @fdiv_nnan_f32(float %a, float %b) #0 {
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; GCN-LABEL: name: fdiv_nnan_f32
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; GCN: bb.0.entry:
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; GCN-NEXT: liveins: $vgpr0, $vgpr1
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; GCN-NEXT: {{ $}}
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; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr1
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; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr0
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; GCN-NEXT: %4:vgpr_32, %5:sreg_64 = nnan nofpexcept V_DIV_SCALE_F32_e64 0, [[COPY1]], 0, [[COPY]], 0, [[COPY1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %6:vgpr_32, %7:sreg_64 = nnan nofpexcept V_DIV_SCALE_F32_e64 0, [[COPY]], 0, [[COPY]], 0, [[COPY1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %8:vgpr_32 = nnan nofpexcept V_RCP_F32_e64 0, %6, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 3
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; GCN-NEXT: [[S_MOV_B32_1:%[0-9]+]]:sgpr_32 = S_MOV_B32 1065353216
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; GCN-NEXT: [[S_MOV_B32_2:%[0-9]+]]:sreg_32 = S_MOV_B32 0
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; GCN-NEXT: S_SETREG_B32_mode killed [[S_MOV_B32_]], 2305, implicit-def $mode, implicit $mode
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; GCN-NEXT: %12:vgpr_32 = nnan nofpexcept V_FMA_F32_e64 1, %6, 0, %8, 0, killed [[S_MOV_B32_1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %13:vgpr_32 = nnan nofpexcept V_FMA_F32_e64 0, killed %12, 0, %8, 0, %8, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %14:vgpr_32 = nnan nofpexcept V_MUL_F32_e64 0, %4, 0, %13, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %15:vgpr_32 = nnan nofpexcept V_FMA_F32_e64 1, %6, 0, %14, 0, %4, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %16:vgpr_32 = nnan nofpexcept V_FMA_F32_e64 0, killed %15, 0, %13, 0, %14, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: %17:vgpr_32 = nnan nofpexcept V_FMA_F32_e64 1, %6, 0, %16, 0, %4, 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: S_SETREG_B32_mode killed [[S_MOV_B32_2]], 2305, implicit-def dead $mode, implicit $mode
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; GCN-NEXT: $vcc = COPY %5
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; GCN-NEXT: %18:vgpr_32 = nnan nofpexcept V_DIV_FMAS_F32_e64 0, killed %17, 0, %13, 0, %16, 0, 0, implicit $mode, implicit $vcc, implicit $exec
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; GCN-NEXT: %19:vgpr_32 = nnan nofpexcept V_DIV_FIXUP_F32_e64 0, killed %18, 0, [[COPY]], 0, [[COPY1]], 0, 0, implicit $mode, implicit $exec
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; GCN-NEXT: $vgpr0 = COPY %19
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; GCN-NEXT: SI_RETURN implicit $vgpr0
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entry:
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%fdiv = fdiv nnan float %a, %b
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ret float %fdiv
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}
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attributes #0 = { nounwind "denormal-fp-math-f32"="preserve-sign,preserve-sign" }
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