https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92190
--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Like (completely untested): --- gcc/config/i386/i386-features.c.jj 2020-01-27 13:20:40.421650866 +0100 +++ gcc/config/i386/i386-features.c 2020-02-03 12:13:23.639161823 +0100 @@ -1764,29 +1764,32 @@ convert_scalars_to_vector (bool timode_p (set (reg:V2DF R) (reg:V2DF R)) - which preserves the low 128 bits but clobbers the upper bits. - For a dead register we just use: - - (clobber (reg:V2DF R)) - - which invalidates any previous contents of R and stops R from becoming - live across the vzeroupper in future. */ + which preserves the low 128 bits but clobbers the upper bits. */ static void ix86_add_reg_usage_to_vzeroupper (rtx_insn *insn, bitmap live_regs) { rtx pattern = PATTERN (insn); unsigned int nregs = TARGET_64BIT ? 16 : 8; - rtvec vec = rtvec_alloc (nregs + 1); - RTVEC_ELT (vec, 0) = XVECEXP (pattern, 0, 0); + unsigned int npats = nregs; for (unsigned int i = 0; i < nregs; ++i) { unsigned int regno = GET_SSE_REGNO (i); + if (!bitmap_bit_p (live_regs, regno)) + npats--; + } + if (npats == 0) + return; + rtvec vec = rtvec_alloc (npats + 1); + RTVEC_ELT (vec, 0) = XVECEXP (pattern, 0, 0); + for (unsigned int i = 0, j = 0; i < nregs; ++i) + { + unsigned int regno = GET_SSE_REGNO (i); + if (!bitmap_bit_p (live_regs, regno)) + continue; rtx reg = gen_rtx_REG (V2DImode, regno); - if (bitmap_bit_p (live_regs, regno)) - RTVEC_ELT (vec, i + 1) = gen_rtx_SET (reg, reg); - else - RTVEC_ELT (vec, i + 1) = gen_rtx_CLOBBER (VOIDmode, reg); + ++j; + RTVEC_ELT (vec, j) = gen_rtx_SET (reg, reg); } XVEC (pattern, 0) = vec; df_insn_rescan (insn); --- gcc/config/i386/sse.md.jj 2020-01-31 19:18:02.395904459 +0100 +++ gcc/config/i386/sse.md 2020-02-03 12:23:40.998100427 +0100 @@ -19819,7 +19819,32 @@ (define_insn "*avx_vzeroupper" [(match_parallel 0 "vzeroupper_pattern" [(unspec_volatile [(const_int 0)] UNSPECV_VZEROUPPER)])] "TARGET_AVX" - "vzeroupper" +{ + if (flag_ipa_ra && XVECLEN (operands[0], 0) != (TARGET_64BIT ? 16 : 8) + 1) + { + unsigned int nregs = TARGET_64BIT ? 16 : 8; + unsigned int npats = XVECLEN (operands[0], 0); + rtvec vec = rtvec_alloc (nregs + 1); + RTVEC_ELT (vec, 0) = XVECEXP (operands[0], 0, 0); + for (unsigned int i = 0, j = 1; i < nregs; ++i) + { + unsigned int regno = GET_SSE_REGNO (i); + if (j < npats + && REGNO (SET_DEST (XVECEXP (operands[0], 0, j))) == regno) + { + RTVEC_ELT (vec, i + 1) = XVECEXP (operands[0], 0, j); + j++; + } + else + { + rtx reg = gen_rtx_REG (V2DImode, regno); + RTVEC_ELT (vec, i + 1) = gen_rtx_CLOBBER (VOIDmode, reg); + } + } + XVEC (operands[0], 0) = vec; + } + return "vzeroupper"; +} [(set_attr "type" "sse") (set_attr "modrm" "0") (set_attr "memory" "none") which fixes the #c0 ICE.