Message ID | 008b01d8a2a1$2ab6ff60$8024fe20$@nextmovesoftware.com |
---|---|
State | New |
Headers | show |
Series | [x86_64] PR target/106450: Tweak timode_remove_non_convertible_regs. | expand |
On Thu, Jul 28, 2022 at 9:43 AM Roger Sayle <roger@nextmovesoftware.com> wrote: > > > This patch resolves PR target/106450, some more fall-out from more > aggressive TImode scalar-to-vector (STV) optimizations. I continue > to be caught out by how far TImode STV has diverged from DImode/SImode > STV, and therefore requires additional (unexpected) tweaking. Many > thanks to H.J. Lu for pointing out timode_remove_non_convertible_regs > needs to be extended to handle XOR (and other new operations). > > Unhelpfully the comment above this function states that it's the TImode > version of "remove_non_convertible_regs", which doesn't exist anymore, > so I've resurrected an explanatory comment from the git history. > By refactoring the checks for hard regs and already "marked" regs > into timode_check_non_convertible_regs itself, all its callers are > simplified. This patch then uses GET_RTX_CLASS to generically handle > unary and binary operations, calling timode_check_non_convertible_regs > on each TImode register operand in the single_set's SET_SRC. > > This patch has been tested on x86_64-pc-linux-gnu with make bootstrap > and make -k check, both with and without --target_board=unix{-m32}, > with no new failures. Ok for mainline? > > > 2022-07-28 Roger Sayle <roger@nextmovesoftware.com> > > gcc/ChangeLog > PR target/106450 > * config/i386/i386-features.cc (timode_check_non_convertible_regs): > Do nothing if REGNO is set in the REGS bitmap, or is a hard reg. > (timode_remove_non_convertible_regs): Update comment. > Call timode_check_non_convertible_regs on all register operands > of supported (binary and unary) operations. Should we use df_ref ref; FOR_EACH_INSN_USE (ref, insn) if (!DF_REF_REG_MEM_P (ref)) timode_check_non_convertible_regs (candidates, regs, DF_REF_REGNO (ref)); to check each use? > gcc/testsuite/ChangeLog > PR target/106450 > * gcc.target/i386/pr106450.c: New test case. > > > Thanks in advance, > Roger > -- >
diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc index aa5de71..2a4097c 100644 --- a/gcc/config/i386/i386-features.cc +++ b/gcc/config/i386/i386-features.cc @@ -1808,6 +1808,11 @@ static void timode_check_non_convertible_regs (bitmap candidates, bitmap regs, unsigned int regno) { + /* Do nothing if REGNO is already in REGS or is a hard reg. */ + if (bitmap_bit_p (regs, regno) + || HARD_REGISTER_NUM_P (regno)) + return; + for (df_ref def = DF_REG_DEF_CHAIN (regno); def; def = DF_REF_NEXT_REG (def)) @@ -1843,7 +1848,13 @@ timode_check_non_convertible_regs (bitmap candidates, bitmap regs, } } -/* The TImode version of remove_non_convertible_regs. */ +/* For a given bitmap of insn UIDs scans all instructions and + remove insn from CANDIDATES in case it has both convertible + and not convertible definitions. + + All insns in a bitmap are conversion candidates according to + scalar_to_vector_candidate_p. Currently it implies all insns + are single_set. */ static void timode_remove_non_convertible_regs (bitmap candidates) @@ -1861,21 +1872,40 @@ timode_remove_non_convertible_regs (bitmap candidates) rtx dest = SET_DEST (def_set); rtx src = SET_SRC (def_set); - if ((!REG_P (dest) - || bitmap_bit_p (regs, REGNO (dest)) - || HARD_REGISTER_P (dest)) - && (!REG_P (src) - || bitmap_bit_p (regs, REGNO (src)) - || HARD_REGISTER_P (src))) - continue; - if (REG_P (dest)) timode_check_non_convertible_regs (candidates, regs, REGNO (dest)); - if (REG_P (src)) - timode_check_non_convertible_regs (candidates, regs, - REGNO (src)); + switch (GET_RTX_CLASS (GET_CODE (src))) + { + case RTX_OBJ: + if (REG_P (src)) + timode_check_non_convertible_regs (candidates, regs, + REGNO (src)); + break; + + case RTX_UNARY: + if (REG_P (XEXP (src, 0)) + && GET_MODE (XEXP (src, 0)) == TImode) + timode_check_non_convertible_regs (candidates, regs, + REGNO (XEXP (src, 0))); + break; + + case RTX_COMM_ARITH: + case RTX_BIN_ARITH: + if (REG_P (XEXP (src, 0)) + && GET_MODE (XEXP (src, 0)) == TImode) + timode_check_non_convertible_regs (candidates, regs, + REGNO (XEXP (src, 0))); + if (REG_P (XEXP (src, 1)) + && GET_MODE (XEXP (src, 1)) == TImode) + timode_check_non_convertible_regs (candidates, regs, + REGNO (XEXP (src, 1))); + break; + + default: + break; + } } EXECUTE_IF_SET_IN_BITMAP (regs, 0, id, bi) diff --git a/gcc/testsuite/gcc.target/i386/pr106450.c b/gcc/testsuite/gcc.target/i386/pr106450.c new file mode 100644 index 0000000..d16231f --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr106450.c @@ -0,0 +1,14 @@ +/* { dg-do compile { target int128 } } */ +/* { dg-options "-O2 -fsplit-paths" } */ + +__int128 n; + +__attribute__ ((simd)) void +foo (void) +{ + __int128 uninitialized; + unsigned __int128 *p = &n; + + n >>= *p ? : 2; + n |= uninitialized; +}