OpenJDK / jdk / jdk
changeset 57506:9b4336f9fa6d
8234228: AArch64: Some temp vars in string_compare intrinsics for processing the last 4 chars (LU/UL) are no use
Summary: Clean up redundant temp vars in generate_compare_long_string_different_encoding
Reviewed-by: adinn
| author | qpzhang |
|---|---|
| date | Fri, 15 Nov 2019 17:02:17 +0800 |
| parents | 10ca494c141f |
| children | aac4eebf5e92 |
| files | src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp |
| diffstat | 1 files changed, 7 insertions(+), 10 deletions(-) [+] |
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--- a/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp Mon Aug 12 16:22:24 2019 +0800 +++ b/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp Fri Nov 15 17:02:17 2019 +0800 @@ -4010,7 +4010,7 @@ // code for comparing 16 characters of strings with Latin1 and Utf16 encoding void compare_string_16_x_LU(Register tmpL, Register tmpU, Label &DIFF1, Label &DIFF2) { - Register cnt1 = r2, tmp1 = r10, tmp2 = r11, tmp3 = r12; + Register cnt1 = r2, tmp2 = r11, tmp3 = r12; FloatRegister vtmp = v1, vtmpZ = v0, vtmp3 = v2; __ ldrq(vtmp, Address(__ post(tmp2, 16))); @@ -4070,18 +4070,14 @@ __ add(str2, str2, isLU ? wordSize : wordSize/2); __ fmovd(isLU ? tmp1 : tmp2, vtmp); __ subw(cnt2, cnt2, 8); // Already loaded 4 symbols. Last 4 is special case. - __ add(str1, str1, cnt2, __ LSL, isLU ? 0 : 1); __ eor(rscratch2, tmp1, tmp2); - __ add(str2, str2, cnt2, __ LSL, isLU ? 1 : 0); __ mov(rscratch1, tmp2); __ cbnz(rscratch2, CALCULATE_DIFFERENCE); - Register strU = isLU ? str2 : str1, - strL = isLU ? str1 : str2, - tmpU = isLU ? rscratch1 : tmp1, // where to keep U for comparison + Register tmpU = isLU ? rscratch1 : tmp1, // where to keep U for comparison tmpL = isLU ? tmp1 : rscratch1; // where to keep L for comparison __ push(spilled_regs, sp); - __ sub(tmp2, strL, cnt2); // strL pointer to load from - __ sub(cnt1, strU, cnt2, __ LSL, 1); // strU pointer to load from + __ mov(tmp2, isLU ? str1 : str2); // init the pointer to L next load + __ mov(cnt1, isLU ? str2 : str1); // init the pointer to U next load __ ldr(tmp3, Address(__ post(cnt1, 8))); @@ -4118,7 +4114,7 @@ __ cmn(cnt2, (u1)16); __ br(__ EQ, LOAD_LAST); __ bind(TAIL); // 1..15 characters left until last load (last 4 characters) - __ add(cnt1, cnt1, cnt2, __ LSL, 1); // Address of 8 bytes before last 4 characters in UTF-16 string + __ add(cnt1, cnt1, cnt2, __ LSL, 1); // Address of 32 bytes before last 4 characters in UTF-16 string __ add(tmp2, tmp2, cnt2); // Address of 16 bytes before last 4 characters in Latin1 string __ ldr(tmp3, Address(cnt1, -8)); compare_string_16_x_LU(tmpL, tmpU, DIFF1, DIFF2); // last 16 characters before last load @@ -4134,7 +4130,8 @@ __ mov(tmpU, tmp3); __ pop(spilled_regs, sp); - __ ldrs(vtmp, Address(strL)); + // tmp2 points to the address of the last 4 Latin1 characters right now + __ ldrs(vtmp, Address(tmp2)); __ zip1(vtmp, __ T8B, vtmp, vtmpZ); __ fmovd(tmpL, vtmp);