Hi, Gently ping it. https://gcc.gnu.org/pipermail/gcc-patches/2024-February/646478.html
Thanks Gui Haochen 在 2024/5/8 9:55, HAO CHEN GUI 写道: > Hi, > As now it's stage 1, gently ping this: > https://gcc.gnu.org/pipermail/gcc-patches/2024-February/646478.html > > Thanks > Gui Haochen > > 在 2024/2/26 10:25, HAO CHEN GUI 写道: >> Hi, >> This patch enables overlap memory store for block memory clear which >> saves the number of store instructions. The expander calls >> widest_fixed_size_mode_for_block_clear to get the mode for looped block >> clear and calls widest_fixed_size_mode_for_block_clear to get the mode >> for last overlapped clear. >> >> Bootstrapped and tested on x86 and powerpc64-linux BE and LE with no >> regressions. Is it OK for the trunk or next stage 1? >> >> Thanks >> Gui Haochen >> >> >> ChangeLog >> rs6000: Enable overlap memory store for block memory clear >> >> gcc/ >> * config/rs6000/rs6000-string.cc >> (widest_fixed_size_mode_for_block_clear): New. >> (smallest_fixed_size_mode_for_block_clear): New. >> (expand_block_clear): Call widest_fixed_size_mode_for_block_clear to >> get the mode for looped memory stores and call >> smallest_fixed_size_mode_for_block_clear to get the mode for the last >> overlapped memory store. >> >> gcc/testsuite >> * gcc.target/powerpc/block-clear-1.c: New. >> >> >> patch.diff >> diff --git a/gcc/config/rs6000/rs6000-string.cc >> b/gcc/config/rs6000/rs6000-string.cc >> index 133e5382af2..c2a6095a586 100644 >> --- a/gcc/config/rs6000/rs6000-string.cc >> +++ b/gcc/config/rs6000/rs6000-string.cc >> @@ -38,6 +38,49 @@ >> #include "profile-count.h" >> #include "predict.h" >> >> +/* Return the widest mode which mode size is less than or equal to the >> + size. */ >> +static fixed_size_mode >> +widest_fixed_size_mode_for_block_clear (unsigned int size, unsigned int >> align, >> + bool unaligned_vsx_ok) >> +{ >> + machine_mode mode; >> + >> + if (TARGET_ALTIVEC >> + && size >= 16 >> + && (align >= 128 >> + || unaligned_vsx_ok)) >> + mode = V4SImode; >> + else if (size >= 8 >> + && TARGET_POWERPC64 >> + && (align >= 64 >> + || !STRICT_ALIGNMENT)) >> + mode = DImode; >> + else if (size >= 4 >> + && (align >= 32 >> + || !STRICT_ALIGNMENT)) >> + mode = SImode; >> + else if (size >= 2 >> + && (align >= 16 >> + || !STRICT_ALIGNMENT)) >> + mode = HImode; >> + else >> + mode = QImode; >> + >> + return as_a <fixed_size_mode> (mode); >> +} >> + >> +/* Return the smallest mode which mode size is smaller than or eqaul to >> + the size. */ >> +static fixed_size_mode >> +smallest_fixed_size_mode_for_block_clear (unsigned int size) >> +{ >> + if (size > UNITS_PER_WORD) >> + return as_a <fixed_size_mode> (V4SImode); >> + >> + return smallest_int_mode_for_size (size * BITS_PER_UNIT); >> +} >> + >> /* Expand a block clear operation, and return 1 if successful. Return 0 >> if we should let the compiler generate normal code. >> >> @@ -55,7 +98,6 @@ expand_block_clear (rtx operands[]) >> HOST_WIDE_INT align; >> HOST_WIDE_INT bytes; >> int offset; >> - int clear_bytes; >> int clear_step; >> >> /* If this is not a fixed size move, just call memcpy */ >> @@ -89,62 +131,36 @@ expand_block_clear (rtx operands[]) >> >> bool unaligned_vsx_ok = (bytes >= 32 && TARGET_EFFICIENT_UNALIGNED_VSX); >> >> - for (offset = 0; bytes > 0; offset += clear_bytes, bytes -= clear_bytes) >> + auto mode = widest_fixed_size_mode_for_block_clear (bytes, align, >> + unaligned_vsx_ok); >> + offset = 0; >> + rtx dest; >> + >> + do >> { >> - machine_mode mode = BLKmode; >> - rtx dest; >> + unsigned int size = GET_MODE_SIZE (mode); >> >> - if (TARGET_ALTIVEC >> - && (bytes >= 16 && (align >= 128 || unaligned_vsx_ok))) >> + while (bytes >= size) >> { >> - clear_bytes = 16; >> - mode = V4SImode; >> - } >> - else if (bytes >= 8 && TARGET_POWERPC64 >> - && (align >= 64 || !STRICT_ALIGNMENT)) >> - { >> - clear_bytes = 8; >> - mode = DImode; >> - if (offset == 0 && align < 64) >> - { >> - rtx addr; >> + dest = adjust_address (orig_dest, mode, offset); >> + emit_move_insn (dest, CONST0_RTX (mode)); >> >> - /* If the address form is reg+offset with offset not a >> - multiple of four, reload into reg indirect form here >> - rather than waiting for reload. This way we get one >> - reload, not one per store. */ >> - addr = XEXP (orig_dest, 0); >> - if ((GET_CODE (addr) == PLUS || GET_CODE (addr) == LO_SUM) >> - && CONST_INT_P (XEXP (addr, 1)) >> - && (INTVAL (XEXP (addr, 1)) & 3) != 0) >> - { >> - addr = copy_addr_to_reg (addr); >> - orig_dest = replace_equiv_address (orig_dest, addr); >> - } >> - } >> - } >> - else if (bytes >= 4 && (align >= 32 || !STRICT_ALIGNMENT)) >> - { /* move 4 bytes */ >> - clear_bytes = 4; >> - mode = SImode; >> - } >> - else if (bytes >= 2 && (align >= 16 || !STRICT_ALIGNMENT)) >> - { /* move 2 bytes */ >> - clear_bytes = 2; >> - mode = HImode; >> - } >> - else /* move 1 byte at a time */ >> - { >> - clear_bytes = 1; >> - mode = QImode; >> + offset += size; >> + bytes -= size; >> } >> >> - dest = adjust_address (orig_dest, mode, offset); >> + if (bytes == 0) >> + return 1; >> >> - emit_move_insn (dest, CONST0_RTX (mode)); >> + mode = smallest_fixed_size_mode_for_block_clear (bytes); >> + int gap = GET_MODE_SIZE (mode) - bytes; >> + if (gap > 0) >> + { >> + offset -= gap; >> + bytes += gap; >> + } >> } >> - >> - return 1; >> + while (1); >> } >> >> /* Figure out the correct instructions to generate to load data for >> diff --git a/gcc/testsuite/gcc.target/powerpc/block-clear-1.c >> b/gcc/testsuite/gcc.target/powerpc/block-clear-1.c >> new file mode 100644 >> index 00000000000..5e16c44fea3 >> --- /dev/null >> +++ b/gcc/testsuite/gcc.target/powerpc/block-clear-1.c >> @@ -0,0 +1,9 @@ >> +/* { dg-do compile } */ >> +/* { dg-options "-O2" } */ >> +/* { dg-final { scan-assembler-not {\mst[hb]\M} } } */ >> + >> +/* Verify that memclear takes overlap store. */ >> +void* foo (char* s1) >> +{ >> + __builtin_memset (s1, 0, 31); >> +}
